thanks for your comments, i think i will switch to a cheaper one until i get pregnant, because the ones i am on are like $23 for 60 and you have to take two a day so they don't last long.
When I started TTC I was taking OTC vit's that I got at Walmart......When I became pregnant, I brought the vit's to my 1st appt. and showed them to the OB and she said that they were fine.......They are like $12 for 274 pills....
If they are prescription vitamins ask your physician if you could get a different prescription for one less expensive. My physician told me not to take regular vitamins when TTC because there are some things undesirable in regular vitamins which are left out of prenatals. Also my physician told me to take any over the counter prenatal until I became pregnant and then switch to prescription. And to answer your question you do need to take them every day the entire month, they have your supply of folic acid in them which is very important to have even before you know you are pregnant.
I am not sure how long they stay in your system. But if they are so expensive maybe right now you could just take a normal vitamin for now. ANd then take those when you are pregnant. Saves you money. Maybe say like 2 multi-vitamins.