When my husband and I got married, we had an afternoon wedding followed by pictures. Then we rounded up our guests and took them to dinner. My husband and I deliberately planned about three hours between the wedding and dinner so that we could have our pictures taken without feeling rushed.
After the pictures were done, we still had about forty-five minutes before dinner. So we went back to our hotel room to relax and ended up having some pretty great post-wedding sex. I looked a little mussed at the reception, but the formal pictures were already done. Most people were too busy eating to notice anyway.
After the reception, like most couples, we were too tired to do anything more than brush our teeth together.
So if wedding-day sex is important to you, you can make it happen by getting creative with your location and time. It doesn't have to be limited to your hotel room at the end of the night.