Brown discharge at 21 weeks?! nervous!

Megan

I noticed last night when I wiped after going to the bathroom there was light brown discharge on the toilet paper. I called the on call doctor and all she said was if it turns red go to the hospital. I thought it stopped later last night but I just went to the bathroom and it's still there. I sneezed and a small brown clot came out which makes me even more nervous. I have a regular doctors appointment on the 8th, should I wait until then or call my doctor when she's in the office. I've never had something like this late in pregnancy.