I have been getting extremely bad headaches, my nipples are purple and I have dots on my areoles which are getting more defined, I have nausea and sometimes I will vomit, I get heat strokes and it gets pretty bad, my boobs are only sore only on the side though, I took a pregnancy test today, which came back negative, my question is, could I be pregnant but just too early to show up?? as my periods are irregular, I don't know when I ovulated or how far along I would be. 

PLEASE HELP MEEE