NEW TO THIS APP BUT I NEED ADVICE.

So I was taking a birth control pill that had completely stopped my period. I took it for a little over a year and a half and I stopped when I noticed it started making me gain weight super fast and it wasn't prescribed to me. So I stopped taking in it February 2016 and I just got my period back in December 2016. I had my period in January but I have not got it yet in February. I have multiple apps that tell me my period is 6 days late. I'm kinda worried but at the same time not to sure what to think. Me and my bf have been together for over 2 and a half years and have never used a condom bc they are always too big on him. He has never came inside me before and always stops when he knows he's close. So idk if I should be worried or not. I've been getting cramps and back aches as if I'm going to start my period but nothing ever happens. And if it helps I did take a plan b pill in January. Thanks for anyone who had the time to read all that lol.