He is grasping at straws and thinks he found a supposed 'weakness' in you. I think its so typical. My H does the same thing. Taking AD's is not bad for you or baby. Lots of normal people take them. Your H should be on meds! Try not to listen. I told you about my visit with my H yesterday and all he could point out was the demise of the relationship was because I overreacted to his and OW's 'friendship'.
If someone put you and your H side by side and listed the character of each of you. You would be tipping the scale on the good side and he knows that.
Me: 46 FWS: 36 Married and Divorced 4/07, Pregnant 7/07,False R 7/07 Baby Girl born 3/08 Kicked him out because OW: 7/08 5/10 He realized what he had and lost. Moved home! REMARRIED 3/14/11!!