I'm freaking out!!!!

On Feb 18 I had a scare. I've been on the pill for about four or five months. My boyfriend put his penis in me unprotected once or twice that night. He never ejaculated in me. I had my period a week and a few days later on March 1st. On time according to eve. It lasted 5 days. I freaked out until this period. We have had sex 9 times this month, but we use condoms and we checked them. NONE of them broke. My period started on time on the 29th and I'm on the 5th day and it's just spotting and old blood. The first two days were heavy and the third day was medium flow. The fourth day was light. I took a pregnancy test the day before my period which was the 28th. It was negative. 
Could I still be pregnant? I don't know why I'm still scared. But I just want to make sure I am safe. Other than the one time, my BF and I use condoms. One has never broken on us. Really just need some reassurance I guess. There's no way I'm pregnant right? The bleeding is way too much for IB and it contained clots. 
Thank you xx