Amniotic fluid low at 29 weeks?! anyone else have this problem and deliver early, on due date? advice please!?

okay so i have been seein my doctor every 2 weeks because the last time i went my fluid only measured 80 ml but he said as long as it doesn't keep getting lower and doesn't get into the fifties that i should just be concerned and not worry myself sick thinking about the baby's safety. well, i went a few days ago, measured my belly w the tape measure, she was measuring small, had my sono and the fluid levels dropped to 71.5 ml...and he seemed a little concerned about the weight gain. after my sono he did and exam to make sure i wasn't leaking fluid...i wasn't BUT the baby is like right there, and could cause me to dilate at anytime, he moved my appts to weekly and said it may be a possibility that i have to go 2 times a week to monitor the baby. just worried and concerned, anyone else go through this or know someone! advice would be much appreciated! thank you!