I think I may not be able to have a baby??

So me and my boyfriend have been together for a year, 6 months prior to us getting together I got my last depo shot. So I was 3 months late for my shot when we got together. Right when we got together I finally started my period again after 3-4 years of not having one from the depo shot. Ever since I've had a regular period and we're both very sexual people. We have sex literally every day some days multiple times (never with a condom). And I still haven't gotten pregnant..? Like how is that? Why can I not get pregnant?? He cums inside me everytime, I've been off birth control for close to 2 years. What could be the problem? Has anyone ever had this happen to you or herd of it before ?? I really want a baby):