Your skin pigment can change while pregnant. I am experiencing something similar except my entire underarm area (where I shave) has gotten dark. I'm really pale so it's extremely noticeable and embarrassing. But I know it'll go away once baby comes and my hormones settle down.
Is the skin kind of dry and patchy? A different texture than the other skin around it? Mine is and a little itchy too. Its not my deodarant, I stopped using any a few weeks ago to see if it would go away and it continues to get worse.
You should be tested for PUPPs (I believe that is the correct acronym?!). Mine is not dry and patchy or itchy. It's just the skin in that area has darkened. Skin problems do arise in pregnancy, some more serious than others. You could call and see if you should move your appointment up.
I don't think its PUPPs. Its not really rashy or red, didnt start on my belly, and is too early in pregnancy... hmmm....what else might it be....
I had the same thing JOy explained with my last pregnancy (in addition to skin tags), I notice it lightening up when my son was about 3 weeks old. He is 6 weeks now and my underarms are basically back to normal.
GRose- thank God I'm not the only one! LOL! My poor husband was completely freaked. He didn't say a word to me until a few days ago. But he kept thinking I wasn't shaving (but of course I was). After a closer look he realized my skin color was just changing. I wish he would've said something to me sooner because I actually did NOT notice until my 2-year-old said, "You're dirty, Mom!" when I was wearing a tank top. I'm so embarrassed that others may have caught a glimpse. Oh well!
mlamorea- I'm not sure. I'm not familiar with skin rashes, irritants, etc. Have you changed detergents recently? Perhaps fabric softener? Our skin can also become sensitive during pregnancy and you may need to try switching detergents. Otherwise I'm sorry I can't be of more help! I just don't know very much about this particular topic.