Test or not?

So me and my boyfriend have been having sex a lot lately. I was supposed to start my period on the 25th of December and it still hasn't come. It doesn't feel like its going to come either. I'm worried and I haven't gotten it yet. Usually when I'm late I will cramp and feel bloated. This time i haven't felt anything. Lately I have just been having abdominal pain and it doesn't stay the whole time. Should I take a test or wait a little longer?