At our imaging place they won’t tell you even if they can guess. Techs are known to be wrong and the earlier it is the more likely they are wrong. Especially since early on girls and boys look a lot alike (like boys). The penis splits apart to become a vagina around that same time. There is a theory about angles that it’s pointing but that’s really hard. For that reason our techs just don’t say anything until the 20 week u/s. You can always ask but they probably won’t or can’t see.