I definately agree with suzy. I did have some discharge when I was pregnant. I also had bad cramps that felt like I was going to start my period but I didn't. If you want to go the cheap route first, you may want to opt to take a urine test at planned parenthood. They are extremely reliable for most people. Although, if you don't get the results you're expecting you'll probably end up with the blood test anyway. So that's like seven dollars down the drain for the urine test.
Blood tests usually run 30-40 at planned parenthood depending on the area you live in. I would contact them as soon as possible.
Good luck and please let us know