Bicornuate uterus and twins!!!😳

Today I went to my first 7 week sonogram and found out that not only are my husband and I having a baby but......we're having TWINS!!! During the sonogram the tech said she believed I had a bicornuate uterus which is unique then she realized there was two fetus with two heart beats. 
Baby A is 7 weeks and Baby B is 6 weeks and 2 days. Question is...... Due to my rare uterus and Gods greater plan. My question as well as my doctors is.... Was Baby B conceived at the same time as Baby A or do we have two separate conception dates?
Anyone have this abnormality or know of anyone that does? Been in shock (blessed shock🙌🏻) today and trying to make sense of all this. I have my follow up sonogram in 2 weeks to check the progress of Baby B to see what's going on. 
Love some insight:)