It's unlikely your periods will be at their usual times for a while, after using Plan B on two separate occasions, so close together. One dose can make your next period arrive at a different time, as it's a huge dose of artificial hormone for your body to deal with. 2 doses, that close together, could really confuse your body, & take it longer to sort itself out, afterwards.
My own experience, years ago, from taking two doses within a few days of each other, was that I got a very heavy bleed that lasted for a couple of weeks, soon after taking the tablets (so heavy I ended up taking myself to hospital thinking there was something wrong), & then did not have any more bleeding for a few months, after that. When I did get periods again, they were irregular.
A lack of periods seems to be quite common for women, if they take more than 1 dose, so close together. Some don't even get the initial bleeding after taking the pills, they just don't get any periods for months.
While waiting for their periods, most of those women I speak with, get a lot of hormonal symptoms. They think they are going to get their periods, but don't get any bleeding.
Everyone's different, though. You may find that isn't your experience.
You won't know when you're fertile, or when your regular periods are due, until you start having regular periods, again. Just letting you know, in case you are trying to calculate your next few ovulations.
The Manufacturer of Plan B advise that you are not protected from any further sex you have, after taking Plan B.
In terms of asking will the pills cover you for any intercourse you have before taking the pills, then it's difficult to know.
Wih regards to the fertile dates you gave at the start of your message, it's worth pointing out that, if you're getting those from an online ovulation calculator, those are just guides, & can vary from woman to woman. Unless you're charting all of your fertility symptoms, each day, then you won't know for certain when you're fertile.
With you being so close to your fertile window, when you had sex, I'd have normally suggested you use the other emergency pill, called Ella (Ulipristal Acetate), had you come here, in advance. That's the only emergency contraceptive pill that's proven can prevent pregnancy during the 24 hours around ovulation itself. You can see that on the Manufacturer's website. Plan B might work at that time, but it has not been proven. Even Ella isn't guaranteed to work, at that time.
If you're in your fertile window when you ask for emergency contraception at a pharmacy, here in the UK, they are instructed to give you Ella, rather than Plan B.
However, you wouldn't be advised to use Ella, so close to using Plan B, as they don't yet know if the 2 drugs could cancel each other out, leaving you with no chance of protection. Ella is a relatively new drug.
Worth bearing in mind in case of future emergencies, though.
Emergency hormonal contraception is not as reliable as regular hormonal birth control. It's just worth a try in a total emergency. It's therefore worth considering putting something in place as regular contraception, if you're likely to keep having sex.
I can't use any artificial hormones, but use the natural method of birth control, also known as the rhythm method, where I chart my fertility symptoms each day. It's a bit tricky at first, learning how to note all the different symptoms, but after a couple of months it's quite easy. We either use condoms during my fertile window, or just don't have sex during that time. Some women like to use condoms all the time, as well as using the rhythm method/natural cycles method, & then prefer to abstain during their fertile window.
Hopefully the pills had enough time to work, for you, to prevent pregnancy. It's possible your ovulation was delayed, as a result, giving you more time for the sperm to leave your body, before you ovulated. Sperm can survive in the body, in fertile cervical mucus, for around 5 days, although it varies from woman to woman.
For further information, another method of emergency contraception, is to have a Paragard IUD, fitted by a doctor, within 5 days/120 hours of the unprotected sex. That can prevent any pregnancy from implanting. It can also be left in place as longer-term contraception.
Hope that helps.