I started taking trinessa for the first time on July the 8th. Me and my boyfriend were having oral sex on the 13 and I took plan b the following day because I thought that maybe some sperm could have gotten in me and it was during the time I ovulate. I had sex on the 16 and used a condom but I'm not sure if we used it correctly. I have been getting lower back pain and cramping for 2 days now but I'm not sure if it is due to the pills. I never get cramping before my period until the day of my period. My period is due 3-4 days from now. I want to know if I could be pregnant or are the symptoms due to the pills. Would the pills protect against pregnancy even though I had only taken them for 9 days when I had sex? Will I even get my period this month due to the pills?