Help!!

I’m 13 almost 14 and ready to have sex (please don’t go comment about my age, I know i am young). I might be losing my virginity to my boyfriend who is 14 this week. The issue is that his dick is 8 inches (ive seen it) and I will be at the end of my period. He says he doesnt care that I am on my period and he is still willing to have sex. I am ready to do this, but I am just scared. Any tips or help?