You should start them as soon as you can. Your Dr can give you a different pill. You can also get the gummies but they don't usually have iron in them.
But I'm only 7weeks and the pills are very large I really don't like them
You're supposed to start three months before trying to get pregnant. Talk to your doctor if you don't like the ones he recommended.
You should start as soon as you find out youre pregnant, and preferably earlier. The folic acid helps stop some developmental problems.