This is more of a curiosity post.... Please read

I have 4 brothers and 6 sisters, all my fathers children 5 are my mothers aswell. My dad was 14 yrs old when he got a girl pregnant she had twins but due to the times (year/era/this kinda thing was not accepted back then) she moved away and he never got to meet them however she did send pics with no return address. At 17 yrs old he was dating the cousin of the girl he got pregnant when he was 14 and also ended getting her pregnant again with twins and again the same situation from above repeated itself. He then met and married his first wife Kathy and had Kara and Amber (not twins) when they divorced my dad met my mom on a beach he was 22 she was 14 (she claimed to be 18 until they were IN bed together) they married when my mom was 17 in 1987 and had 4 pregnancies end in miscarriages 2 of them were twins the other 2 were just 1 baby finally in 89 my brother jeromie was born in 91 Josh was born and in 92 Lynne was born they intended on stopping there but I popped up in 2000 my dad got a vasectomy since he managed to beat birth control but he never did the follow up to make sure it healed correctly and would fully prevent it. That was until 2008 when my little sister popped up and he found out he has a partially successful vasectomy with a 72% chance of prevention but a 28% chance of pregnancy likely with someone that's highly fertile (aka my mother) now that you have my sibling story what I get from my family as far as family history and twins is that they run in both sides heavily and I am most likely to have them..... My S.O. has Twins that run in his family aswell.... Can someone that truly knows and understands twins and their conception give me a bit of an idea what i may be "in line for" as my family calls it when they say im "most likely" sorry its so long but its alot lol