Pregnancy stretch marks. *To much info*

So last night I was using the potty after I was done I pulled my panties on and looked at my butt in the mirror cause my SO was wanting to look at my but this morning. Well while doing this I saw a strange mark kind of near my butthole area. So I opened my cheeks and saw that I have these unusual veins that are dark in color around my hole/crack area. Now I barely noticed these marks I think they have been there a few weeks. Could they be stretching from my pregnancy or should I be worried? I cried last night and asked him if he noticed and he admitted he did but didn't want tell me cause he didn't want me to feel insecure about myself.