miscaarriage, pls help

me & my husband been trying to concieve. he lives outside united states (still waiting for his visa) so i just come home to see him once evry year. i went back last 2003 to see him and when i came back to U.S. 5wks later i found out i was pregnant i went to department of health and they set me up for a schedule and told me to come back next week for an appointment. 3days after i was spotting evrytime i use the bathroom... i went to emergency room & they told me i'm having a threathend miscarriage & they can't do anything about it. so it happen. i went to a good physician and told wahat happened she gave me a ther rx prenatal vitamins and i took it for almost a year until i went back home to see my husband. after 2mos of trying we made it again..we we're so excited... we went to a doctor and gave me a diffrent vitamins and told me to stop what i was taking (ther rx)..so i didcontinue taking it. they said they don't know what it is. because phillippines doesn't have that kind of prenatal vitamins. they gave me duphaston and iron vitamins. after 8wks i miscarriage again. i didn't have d&c. i bled for 1week just like regular period not that heavy. nxt year we want to try again.. pls help what should i do i'm thinkin of taking precare concieve again & don't stop it eventhough they tell me.... wee really want to have a baby. is 3rd time gonna be more risky? do i need to bed rest the whole 9 mos? pls help!!!

thank you somuch!!! god bless!!!