So I made a stupid mistake and got caught up in the moment and had unprotected sex with my gf on July 17th. I bought her plan b one step that day and she took it 3 hours later. About a week later she got some light bleeding for about 3 days then it stopped. She didn't get her period for the month of August and its now the beginning of September. Her period was a bit irregular beforehand but we don't know if that's the case now. I understand that plan b one step is not 100% effective. But she took it within 3 hours after unprotected sex so I thought that it would be most effective then. Also she has a bit of nausea sometimes and some cramps sometimes. But that's about it and I've read that those are some side effects of plan b one step as well as messing up the menstural cycle a bit. Its just that its been 6 weeks now and she hasn't had her period and we're freaking out. Is it likely that she's pregnant?