I'm 19 Years Old, Me And My Boyfriend Are Sexually

I'm 19 years old, me and my boyfriend are sexually active about once a week. I'm not on birth control pills but we use condoms every time. He stuck it in without a condom for maybe 2 minutes then put a condom on. This was a couple days ago. He checked for precum and wiped a little bit off. He never comes close to ejaculating inside of me even with a condom on. I always finish him off as we are scared of getting pregnant. I'm supposed to get my period tomorrow and today I got some light cramping and finally saw a little bit of light pink blood. I put a tampon in and there was nothing when I took it out hours later. I don't know if ik just freaking/stressing myself out about it and it's throwing my cycle off or what but I'm really nervous but also trying to convince myself there's very very little chance that I could be pregnant. Please help!