Aqua, my baby's HB at 6 week was 128, at 10 weeks it was 168 (thought for sure girl...lol) and at 18 weeks I think it was about 154 or so. My girls were always between 148 and 160. Plus, I have heard women saying their son's HB's were like 170 and above, so I don't if I believe in that OWT, but I do think the urine pH is more accurate than anything else. From reading all the urine pH polls they all point to it being a good predictor of gender.
The girls are very excited, but what's funny is my 5 yr old has always referred to the baby as her baby brother..she would even tell people that she was having a baby brother and I would have to say we don't know and you could have a sister. She would of course, roll her eyes at that thought.
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Maz, I definitely would not give up hope. When is your big u/s? I don't know if I know a single gal on here who has had a pH above 6.5 and had a girl. According to that poll I did, someone had or is having a girl with frothy bubbly wee, so I wouldn't put too much into the bubble theory I guess? Maybe the baby had the goods tucked up and it appeared girly? FX crossed for you :)
So, when is everyone's big scan?