Dear OFB readers: I've had sex with 4 men, is that too much for an 18 year old?

From a female OFB reader

I am 18 years old and in my second year in a private university. I started having sex when I turned 16 after leaving secondary school and I have had four sexual partners so far. I dated 2 of the boys while the other 2 were just flings. Recently I confided in a friend the number of men I've been with and I later saw text exchanges between her and another mutual friend of ours laughing at me and criticizing me. They called me all sorts of names including wayward and loose. I've been with only four men, is that too much for a girl my age? I thought it was the norm so why are my friends condemning me and passing the info around?

Four sexual partners at 18? 

That's waaaay too much! My opinion. What do you guys think?