Sores :( (little tmi)

This may be a little tmi but I an 38weeks my 1st pregnancy and early in my pregnancy I would get a pimple like sores on my upper thigh and or on my lower but cheaks.. I didn't think any thing of it I tough they were just heat bumps cuz Im not really big but I'm not a stick figure kind of girl and they went away for quite some time and these last few weeks they are coming back and I'll have like one or two at a time... They have liquid in them like a pimple would but there bigger thin a normal pimple and are now leaving behind dark colored scares even if I don't mess with it and just let it be.... Does anyone have any ideas what theses would be or have had them as well ?? I'f so how do I get them to go away and stop hurting me??