please help!!!!

I have been on the pill for a little over four months now. In Feb 18 I had a scare. My boyfriend put his penis in me unprotected once or twice. He never ejaculated in me. I had my period a week or so later. On time according to <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">eve</a>. It lasted 5 days. I freaked out until this period. Which started on time and I'm on the fourth day and it's pretty light. The first two days were heavy and the third day was medium flow. I took a pregnancy test the day before my period was due this month. 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 
Thank you xx