37 and TTC

I’m 37 and TTC baby #2. Baby #1 is almost 4 years old and was conceived naturally and straight away but afterwards I had bleeding for years when having sex and never got to the bottom of it (saw a few doctors but nothing visibly wrong that I know of). We’ve been trying for 4 months unsuccessfully and I’m starting to worry that we left it too late now. Anyone else similar age who had no issues with first pregnancy having similar troubles with the second?!