Need advice

Hi everyone I'm new to this site but really in need of advice... I got pregnant last march - it was our 1st month trying- and miscarried in April at 5 and a half weeks. I then didn't have another period for 48 days, is this normal? We have also been trying ever since we miscarried but with no more pregnancy's in the 8/9 months trying. I am getting really depressed and disheartened each time my period comes, my cycles range anywhere from 28 days to 33 days so I find working out when ovulation is difficult and people tell me you should try the day before you ovulate is this right?  at only 21 the doctors won't do anything to help me as I have conceived before but is it normal to take so long at a young age?