Boyfriend

I'm supposed to go to sun and fun with my boyfriend tomorrow but I started my period I wear tampons so that's not a problem but idk he isn't comfortable with my period. He said he will try having period sex with me. I just feel like he will be bummed. Idk I just I'm afraid I guess you can say I'm afraid that he won't think I'm sexy or something. Today he helped me pick out my bikini and he said it was sexy but idk. Should I tell him on my period? I just don't want to disappoint him. We are crazy for each other sorry I just wanted to vent..