I did have sex several times before I noticed and then I double up. Now I'm my fourth day of the week I should have my period, but haven't gotten it yet. I also took a pregnancy test and not pregnant. I've been on the pill for about 3 years and been very good at taking it on time. This was a freak incident. Can I be pregnant? Plus, I used an over the counter yeast infection insert the week before. Not sure if that's relavent.