3weeks Later...

It's been 3wks since i miscarried and a little over 2weeks since i stopped bleeding. Is it true that women become very fertile after ? We had sex almost everyday since i stopped bleeding. I have an appointment in two days with my Doc .. Should i ask for a prego test ? Do you ladies think i could of conceived again already ? Im having to pee often , tugging cramp like feelings & my lower back just aches (on & off) for the past week.