Pain in lower left side- AF due 4/26

I have been having a dull cramp-like pain on my lower left side for the last two weeks. 
My husband and I have been TTC for 5 months, and this pain is driving me CRAZY. 
I'm hopeful it's an early sign of pregnancy, and terrified it's something else.
Has anyone else experienced a pain like this before? Did it turn out to be a bun in the oven?
I'll be testing tomorrow morning!