 [ Symptoms ] missed birth control could i be pregnant  i missed one of my birth control pills during my last week of pills before my week of placebo pills i had unprotected sex during this time frame unaware i had missed a pill sometime during the week i took the last two pills on saturday when i realized my mistake and i should have started my period by now what are the chances i might be pregnant [ Disease ] hi perhaps you are allergic to something associated with sex e g condoms lubrication gels vaginal juices perfumes etc or possibly something you consume before sex keep a journal of everything associated with sex and the hives and perhaps you will find the culprit try using latex free condoms that could really be a big part of your penis problem as for hives that could just be down to you as this is totally natural in desmond morris is book the naked ape meaning us he has a whole chapter on the sex hives or rash that some people get across their chest shoulders belly or back hope this helps you good luck