Is it bad I haven't been taking prenatal vitamins?!

Madeline • I'm 26, husband is 31. We've been married 6 years and had our first baby 7/15/16 and are now due again 4/17/19
I'm almost 6 weeks pregnant with my first but haven't been taking prenatal vitamins cuz I totally forgot!!! Is this bad?!?!?! Feeling worried....