Dark spots on skin

Haley • Expecting my rainbow baby next March 2019🌈🤰🏻

I have seen this for a few weeks now, but didn’t think anything of it till I found out I was pregnant, I have looked it up with a little bit of research I want to believe it’s a common thing it says women experience skin discoloration. This is on the inside of my thigh. Can anyone else relate? Should I be worried.