My girlfriend is pregnant! ...how do I tell my parents?

CC

So my girlfriend is 16 and I'm 18. We're both genderfluid and up until Saturday we were in an open relationship. A guy came up to my girlfriend at school and mentioned how he really wanted to lose his virginity on Friday the 13th. Flash forward to now, we find out she's pregnant and he's the only way it would have happened. We're both excited and scared and definitely keeping the baby. How on earth do I tell my parents? My love already has a plan, but me? No clue. Ahhh!