Avoid sa first trimester regardless kung high-risk ka or di naman. May cases kasi na nag sex and no complications, bigla nalang magkaka threatened miscarriage dahil nga nakipagsex. Very critical kasi first twelve weeks, prone to miscarriage so tiis lang konti. And ask your OB nalang din if you want. I was told to avoid til 2nd trimester.
https://ph.theasianparent.com/sex-myths-during-pregnancy-stop-believing