Who or what is in the lower left corner? How many vibrators dose she intend to jam down there? Tape can solve many porblems, but this isnt one of them.
Her aprony-thing is black with white frills, just like Marisa's outfit. The white dots on it could represent the white buttons on her bodice. Also, she has a puffy white sleeve (top left-most corner) just like Marisa.
As for being pregnant...that could be the result of two fanons: 1) Touhou girls reproducing with other girls, and 2) Marisa's harem. You have THAT many girlfriends, one of them is bound to getcha pregnant.
My guess would be, a mouth biting down on some taken off panties?
someone holding their dirty panties with their mouth.......I know crotch sweat and urine stains on panties is a fetish, but faaaaaaark me, that one is past the point of vomit inducing disgusting.