Sex with Coppergaurd

Okay, so ever since I've gotten my Coppergaurd over 6 months ago I'm been having sex freely.. And by that I mean with my one boyfriend but no condoms.. He's always came inside of me but only pulled out like 2 times. But I always get my period.. So I expect nothing wrong. But I'm worried about getting pregnant, I allow him to cum inside me because we never suspect anything because mi do get my period and when I get it I get my period for about 10 days :( but should I be concerned about letting him cum inside me ever so often?? We have sex every 2/3 days and sometimes more than once a day! So just give me some tips..