Am I Pregnant??

My husband and I have been trying to conceive for over 2 years now. We're 21 & 23 (optimal fertility ages) yet haven't been able to get pregnant. We're going to start Clomid at our next appt but I feel like I may be pregnant now. I'm bloated, blue veins along my breasts, tired all the time, consistent headaches, cravings, and over the past 3 days I've been a peeing machine. I took a ClearBlue digital pregnancy test and it came back "Not Pregnant". I feel like at this point maybe I'm imagining my symptoms because we want a child so bad and have been trying for so long. Am I crazy or is it a possibility? What were your early pregnancy symptoms?