prenatal pills importance ?

I know people say its important to take them , my obgyn also prescribed me some iron pills the iron pills im okay with taking its just the prenatal pills that I dread taking .. I never really had a problem with them till one day I just threw it all up maybe its cause I didnt really eat that morning idk but I have not experienced morning sickness at all these 3 months ive been pregnant but I just hate the taste of the prenatals now and I usually take both the prenatals and the iron pills together at night but I forget to take them sometimes up to 4 times a week . I dont want it to affect my baby but if theyre not important to take after a certain amount of time i'd rather not . any opinions ??? at my first ultrasound appt . I found out I was 8 weeks pregnant so I didnt really take them at the important part of development of my baby