Supplements and fetus development.

Can anyone tell me if there is a possibility that during the first sonogram and the length of the fetus which indicates the date of conception is usually accurate. Or can supplementation with high quality prenatal vitamins, DHA, Moringa, Iodine, coconut oil, and apple cider vinegar and a good diet of fresh fruits and veggies, limited meats ect accelerate the development of the fetus and portray being pregnant longer than she really is or are they usually pretty accurate. Thanks for the input. Tweet