Hi Taegan,
I am 26wks with B/G frat twins.(First occurrence in family history!) Congrats to you!!! Frat twins are more likely developed by hormone levels due to the pill, age of mother or the production of two eggs in one cycle. The chance of of it being genetic is not common but can occur. Good luck with the scan on Monday. Hope all goes well for you!!! I hope this helps a little? Kim xoxo