Fertility Testing

I know many people say doctors won’t do any fertility testing until at least a year of conceiving, but I am getting impatient. We’ve been TTC going on 4 months, and I really feel like something must be wrong. We conceived our son first month TTC. I had a c section and never felt like I properly healed (even tho doc said I healed fine). If you insist on testing before one year, will doctors do it? What is the purpose of waiting 1 year to test?