Help.

I'm confused been thinking about this for a while. In February this year I got positive tests with clear blue & negatives with pink dyes. I didn't have a period until cycle day 44 mine are usually 26-28 days long. I went to the hospital the day my period started they said there wasn't any hcg detected. Could I have possibly been pregnant? I'm 20, that has never ever happened before. What are your thoughts on what could've happened? I think my period could've been late but why was the test picking up pregnancy. I know blue dyes have false positives I didn't know until after that happened. Thanks.