Period-like-cramps 39wks2days

She • Excited mom here! :-)
I'm having a period-like-cramps since last night. 😞 It is intermittent. I can still tolerate the pain. Its kinda painful after few seconds or minute the pain will be gone. When I had my ultrasound my baby is already low and she's in her position(cephalic) already. I don't have any water discharge except for the normal discharge I have yellowish greenish just like white mens. My OB said to observe it first and if I cannot tolerate the pain that's the time I will go to the hospital. I'm nervous yet excited since we've been waiting for my baby to come out. Waaaah.