HELP!!

So last month I was almost positive I was pregnant, because I had all the symptoms and AF was two days late. I was really disappointed, but AF didn't seem normal either. I normally get terrible cramps and I had minimal/no cramps. Also, the ones I did have didn't last for 2 hours like other period cramps would. Now I've been getting oddly lightheaded after supposed af showed, and I stepped on the scale and it said I weigh 10 pounds more than I did last week?!?! I've been eating clean and excersizing so I don't see that as actually being possible (yes I re weighed myself a lot to be sure) so can anyone help me understand this? Could I possibly be pregnant?