fainted

Kelly

I'm 18 weeks and today me and my SO went fishing like we do almost every weekend. I wasnt hot it actually felt cool. I had been eating/snacking all day. I stood up to help my SO with something. while standing not even two minutes my sight got bad and next thing I know my SO is trying to see if I'm okay. He said it happend so fast he couldn't catch me. I feel fine besides my butt and back hurt alittle and I have a bad headache. Has this happened to anyone, do you know what caused it?