Has anyone else been put on pregaday tablets?

im 31 weeks pregnant and had my anti d and blood tests done on friday, i received a phone call from my doctors stating i had a prescription and blood test form to pick up. the prescription was for some tablets called pregaday and i have to have another blood test in four weeks. i first i was given these because i needed iron but if that was the case wouldn't i just have iron tablets? anyone else had this? do you know the reason i may need these? the main ingredients are folic acid and iron. i am going to ring my doctor and find out from her but just wanted to see what you lot think, thanks