Can we have sex during second trimester of pregnancy? Is it safe?

I had sex at week 14 and 3 days later I woke up to a gush of blood which wouldn’t stop so I was rushed to a & e, doctor checked and baby was fortunately still healthy, cervix still closed, but great amount of bleeding and clots around cervix. Was immediately injected with progesterone, put on antibiotic drip for 2 days and hospitalised on full bed rest and monitored for 2 days. Now in bed rest for at least the next 1 week. Doctor says that sometimes infection can occur due to sexual intercourse in certain cases, so do be mindful.