I've been on my feet at work for about 10 hours with short breaks occasionally to sit. I'm experiencing sharp pains kind of in cervix/uterus up my vagina. Is this just from being on my feet all day? This is the first time it's been this bad. I am 16 weeks tomorrow and have an ultrasound to find out gender in the morning SO NERVOUS! I have this fear of missed miscarriage even though I saw the heartbeat at 8 and then 12 weeks.