Underage marriage by pregnancy/same guy have to be your husband/ marriages?

now i will state right now that i am NOT pregnant, but this seems like an interesting loophole, and i wonder if there is a law about this scenario. im 15, and my fiance is almost 17 (18 in a few months). my mother (no father) particularly hates him, and her consent to marry him is very unlikely. now say i was pregnant by him, and was waived past her consent to marry, then got an abortion once it was all final. would that nullify the marriage or are you still married? and if it is nullified, would i be back under the jurisdiction of my mother or would i be a free person? and another question i just thought of: if you do get married by pregnancy, does it have to be to the man that got you pregnant (although whether he would want to marry you once knowing it wasn't his kid is dubious) or could it be anyone? what if you were a and empregnanted by that thing where they put a cell nucleus of the one woman and put it into the ovum of the other woman to make a fetus? would it be legal because you were pregnant by them or would it be illegal because of the 'no gays allowed' policy of marriage?