Late period


Hi guys, my name's Shy. I've been trying to conceive for about 6months now. My period is currently 8 days late but a day or so ago, I took a PT around 6pm and it came back negative. I've had some mood swings(anger and sadness to the max) , my stomach has felt like it was going to stretch so far that it would explode EVERYTIME I eat, and I've been super tired. I've never been pregnant so I don't know exactly what symptoms to really look for and I know everyone's is different. Any ideas on when I should be testing next and what other symptoms to be on the look out for? Thanks :)