Spotting with Crinone (progesterone gel)?

Anyone else on progesterone and having spotting? Last night, about an hour after I inserted the gel, I had a little cramping and brown discharge after I wiped. I kind of figured this might be a build up of the gel, as this stuff is pretty gross! I didn't have any more spotting after that. Then, around lunch time today, I used the restroom and had very light pink on the toilet paper after wiping. Nothing else since. I was scheduled anyways tomorrow for my first ultrasound at 7w6d. I notified my Obgyn and was told to go for the ultrasound tomorrow and call them back if it turned into more of a bleeding. So far, so good, but with 2 miscarriages, it was just enough to make me nervous!