Numbing would be a PITA but it's not as bad as I was imagining (paralysis of the jaw with associated drooling lol).
It's worth keeping in mind that dental issues often do flare up during pregnancy (I can't remember why because I haven't been pregnant for ages). There used to be an old wives tale that you lost a tooth for every child

If your dentist says that it will have to go eventually I think it's better to go sooner rather than later. Cost wise, it's cheaper to get rid of it now instead of paying for cleaning and to deal with flare ups and then paying for removal. Pain wise, it's the same deal. The pain of flare ups followed by the removal or the removal straight aware and eliminate the flare ups from the picture.