Help!! Am I miscarrying?!?!

Liz
I've been having faint positive hpt's since thurs, and I've been having mild cramps since then too. Today I've had a couple of really bad cramps, and now I (tmi!!) had a little really pale pink discharge when I went to the loo- I'm so worried its a chemical pregnancy... any ideas?! AF was due last Sun. Supposed to see the obgyn on thurs to confirm the pregnancy. Help!!