Could a vaginal exam very early in a possible pregnancy upset the cervical mucous plug?

Patient: I had protected sex (using a condom) on day 7 of my cycle. On day 13 I noticed a very light spotting that lasted a few hours. I know this could possibly be due to implantation bleeding (among many other things), but it is likely too early to take a reliable home pregnancy test. I have a vaginal exam for a diaphragm fitting on day 20 of my cycle. I want to know if the fitting would upset any cervical mucous plug that may be in place, or any possible early pregnancy in general.