Help please!

It's crazy how you could know nothing about sex but be so great at it! So the first day of my period was November 28! My flow is never heavy and let's be honest...... That's when most of us are the most horniest! I had sex almost everyday on my cycle and my bf came in me the day it went off but then my cycle came on so I wasn't worried about being pregnant. December 17 he came in me again full throttle ... 2 days later I took a test and of course it came out negative. Should I carry on with my life or take another test later on this month? I just feel like this could never happen to me ...