Sex on Period

I'm on Cerelle and unfortunately it makes be spot every single day, and it's always the lining that comes out (sorry for the tmi) and the other day, it was really light, so light I wouldn't even call it spotting. So me and my boyfriend decided to have sex and the worlds most embarrassing thing happened. Everything was good and then we moved from me being on top and there was blood everywhere. I bleed really heavily and unfortunately what we thought was just me being wet was actually blood. I was so embarrassed and I didn't know what to do. He was not bothered in the slightest (and if he was he did a really good job at hiding it) but I was. I was mortified. I just want to know what you guys would do? It's put me off sex until I can get my contraception changed because I don't want to see that again...