Since you are 9 months pregnant meaning you are being seen by a Dr. often why don't you ask his/her opinion -- at least so you may ease your mind in the interim (until after the birth & the settling in period). It probably is nothing but promise yourself that you will have it looked at very soon after the baby arrives. Melanoma is nothing to play around with & should not be put off.
I put off going to the Dr. for 2 years and according to the Drs. that was insane. If it had spread I might have been a goner and it does not take long -- just several months. I had 41 Drs. involved in my case because I had the highest level of the disease & it had not spread they wanted to research to find out why. They took some tissue of mine to grow in a lab somewhere to study to find out what is unique about my cells.
I am happy to say I reached my 10-year mark in December & am pregnant with my first child. (I am 39!) I do not take any chances -- no sun, no tan, no risk. What is great about that is that I get an A/C enviornment always, get dropped off at the front doors of anywhere I go, no sweltering heat to endure to get that "healthy glow", and not worrying about something as petty as darker skin.
Good luck to you & doubt you have anything to worry about but check it out soon. By the way, my cancerous mole did not look like the pictures I have seen in the brochures.
Don't let me scare you. I just try to educate people since this disease does not get much exposure. If I tell people that I have had cancer & they ask what kind when I say skin cancer they are kind of like "oh, well that's nothing". Gotta get the word out. STAY OUTTA THE SUN & THOSE STUPID TANNING BEDS!!!! The people running those places will tell you how safe they are but they are the ones who stand to profit. Protect yourself. I still have a brother-in-law that teases me about being pale. I am alive & happy. He just never got it. Just goes to show how little attention is paid to this.
Take care & protect yourself. Wear your sunblock.