Having Sex For The First Time Two Days Before My Period?

So I'm going to have sex for the first time tomorrow but I'm supposed to start my period Wednesday. There are days where I start a little earlier than my calendar says. I'm just wondering if this is a good idea or not? I just started getting a little crampy today and my face was broken out yesterday. Usually I get crampy 2 or 3 days before I start my period but I know that sometimes when I masturbate with a toy it can cause me to start my period. I'm wicked excited for tomorrow since all day tomorrow is going to be great. I just dont want to start my period right in the middle of having sex. Should I try it and see what happens and bring along some pads and tampons? Also any tips on ways to maybe delay it a little without taking birth control?