Is Pregnancy Possible Within 4 Weeks Of Miscarriage?

hello there i had a misccariage 4 weeks ago i was 5 weeks and 3 days and the doctor at the hospital saud i misccariaged really early now 4 weeks later i and getting the same symtoms i did when i was pregant before, one week after i misccaiged i have been having sex so am i pregnant, how can i count my dates pls help