No Flo, neg test!

Hello Ladies! I'm new to the boards and have been TTC for 2 years but only on the first cycle of Clomid. I am well over a week late now but my urine tests come up neg.! I'm TIRED and nauseated but I think that may be the Clomid talking from what I've read. I went to the doctors today to get a blood test so I should find out tomorrow if I'm pg or not but has this happened to anyone else? There is no sign what-so-ever that Flo's gonna show up at all and girls, I am NOT leaving the light on for that woman! let me tell ya! Is it common for Clomid to actually STOP you from having your period? Kinda scary if you ask me! Any advice is appreciated!