Starting to give up

This is my third month trying to get pregnant and I didn't think it would be this hard! I'm in my early 20's so I was thinking maybe once or twice was all the trying I needed to do. I just receive what I think is my period but I'm not for sure its kind of light than what it normally is and I have a weird feeling in my lower stomach it's like a tight feeling. The top part of my stomach has also been feeling weird and I have been entirely too sleepy and craving foods lately. I'm wondering can I have a light period and still be a chance that I'm pregnant or am I just being too hopeful?