IS IT NEARLY IMPOSSIBLE? !

I am 19 he is 20.

I was on my period and skipped about 3 to 4 days on birth control because the pharmacy was out and I had to work and couldn't get time off to drive an hour away.

My boyfriend and I had sex on Sunday and he ejaculated inside of me. I did use spermicide before sex. We are NOT trying for a baby. I am in the firsr semester of nursing school.

I took my birth control the night before and every night since.

I had my period on the 6th and 7th.

My fertile window is the 17th through 22nd. This happened on the 12th.

It was a couple days after my period so we thought it wouldn't do anything but my birth control was not in my system anymore.

What are you opinions?

Thank you in advance.