Help!

I just recently got my period or at least what I thought was my period but somethings still doesn't seem right. I'm usually super heavy and my period always last for 7 days but this time it was 4 and I was only somewhat on the heavier side for one day and the other 3 days I was just super light or spotting. Plus I feel super sick I keep having hot flashes and I'm super sleepy also I'm having super bad cramps. But I took a test and it said negative should I test again could what I thought was a period be implantation bleeding? I would be so excited if I was pregnant my husband and I have been trying for almost 2 years now.