Confused!!

Deanna
Went to ER at 16 weeks for pain and OBGYN told me its a girl she could even see the vulva....18
Week appointment couldn't find a heartbeat so they did a quick ultrasound and OBGYN said its a boy!!! I'm so confused. I have my 20 week ultrasound next week I hope it's a girl!!! Based on the scull theory what do you guys think?