I had obimin throughout my pregnancy. Fish oil was prescribed to me during my second trimester, and additionally iron tablets in my last trimester. I wasnt prescribed calcium, so i just drink milk etc. Your doctor will advise u on the supplements to take at diff stages so not to worry. Balanced diet is still key as compared to supplements.
I was given calcium and fish oil from week 13. Multi-vitamins was given probably at week 8-9