ilang weeks po before makita si baby via ultrasound? i'm 3weeks pregnant po

6 weeks na ako in 2 days but sabi ng ob around 7 1/2 weeks. Gusto ko na sana mag pa ultrasound kasi nakakaparanoid haha but sunod nalng tayo sa ob para sure. Hopefully meron ng heartbeat by then. (Sabi din ng ob na we will see the heartbeat pero ayaw muna nya gamitan ng sound thing pra marinig ung heartbeat since super early pa) she’s from st. Luke’s bgc Idk if that’s normal