Don't want to get my hopes up :(?

Me and my hubby had unprotected sex on Thanksgiving. We have been TTC for over a year. I get my period 2 times a month so it's hard to tell when I am ovulating. I usually get the 2nd period around the 22nd of each month. My first period always comes on the 10th for about 5 days. This time the 2nd period didn't come till the 30th and it was really really light and it was just light brown mucus spotting (sorry TMI). I was supposed to start today and nothing just cramps and I have been constipated my back aches which never happens when I get my period or am about to start. I don't want to get my hopes up but it's odd that my 2nd period was very late and very short and that I haven't started today. I have also had a tight feeling in my lower abdomen when I stand, could that mean something? I want to test but I am scared it will just be another negative.

Any advice :( I'm about to give up hope on us having a baby.