At 21 weeks I got a ultrasound done but I didn’t want to know the gender until the reveal in the envelope it only said “Boy” ... And everybody keep saying they gonna laugh if it’s a girl blah blah blah !! His heart rate stays high in the 170’s lowest 154 .. and the nurse thought I was having a girl becuz of it .. I really wanted a boy .. idk when my next us gonna be I’m 28 weeks and 2 days !! And I just want them to make sure I’m having a boy !! I didn’t see his penis so I’m not sure for myself lol !! Can the gender be mistaken ?!