We used a condom, but instead of just using one we used two

Im 18 and recently have had sex with my bf. We used a condom, but instead of just using one we used too,    i know its probably not recomended, but he said he had done it before and its worked pretty well for him. each time that we have had sex we checked the condoms and none of the times they were broken. I know hormones and stress can affect your period so it may be either one of those. But i am two days late. please let me know what i should do :S