19 weeks. Is my baby okay?

I went to the dr for my ultrasound to find out if it’s a boy or a girl (I already knew its a boy I found out at 15 weeks) and when I was in the room having the ultrasound done she said everything was looking good and told me that they were having trouble seeing his face and heart so I could come back for another ultrasound in 4 weeks but we heard his heartbeat and it sounded good they said. Then a different doctor came in to talk to me about the ultrasound and they said that the placenta was a little low and that I needed to refrain from sex and don’t be on my feet for long periods of time she said I’m not on bed rest but just don’t do a lot of exercise that will put strain on my stomach.. also said that my blood pressure was a little high and it could be caused by stress and they told me not to stress but idk how I’m just worried about my baby boy💔