Help please...

My husband and I are trying to get pregnant. My period was May 7 & 8th and that was it. My normal periods are 5-6 days long. My boobs started really hurting and I've been having cramps but nothing was happening, so I took a pregnancy test and got a positive (yay!!), we took three more across last weekend all resulting in a positive. We were exstatic! I had been having some anxyiety about maybe having false positives that had been waking me up and even infiltraiting my dreams all week... So friday afternoon I took another test and it came back negative. I was so confused but I figured it has to be wrong and I'm really pregnant. So I told my husband and he suggested taking another test this morning (sunday). We used the Clear Blue test that says how far along we are as well. (We had used one before and it said (positive 1-2which  means 3-4 weeks). But today it says not pregnant...  I'm confused and angry and sad. What's going on?!