Pregnant or paranoid??

Keana
My husband and I have been TTC for a couple months. I got what I thought was AF on March 5, two days earlier than expected. I had been having cramps for five days leading up to it. I started spotting on March 4 with a million pregnancy symptoms (okay, like 4) and started getting my hopes up. So when AF came the next day, I was very disappointed. However, even though it was heavy, it only lasted 2.5 days and ever since Ive been feeling super fatigued and nauseous on and off and my boobs feel fuller. 
Could AF have been just heavy breakthrough bleeding? Is it even worth taking a test? Help?!