12 weeks today and still so sick, barely been able to take my multivitamins. Worried about spina bifida

This pregnancy has been horrendous, im sick all the time! Ive barely been able to take my folic acid. Im not doing the test for downs mainly because i missed my appt with my doc to get the referal. But im extremely paranoid about spina bifida now because with both my boys i was able to take my multivitamins.

Have any of u ladies struggled with this and had a healthy baby? Honestly im very scared. Is there any tests they can do? Im probably over reacting but i really havent been able to take them much.