VBAC is possible depending on angle of cut on my uterus

Last year in Feb I gave birth to twin girls at 29 weeks due to TTTS(Twin To Twin Syndrome). I was in stage 3 of TTTS and the doctors tried to keep me pregnant for another week but Baby B heart rate was making my doctor uncomfortable. I remember them describing the type of c-section I’d have. Non emergency, bikini cut and spinal. They never mentioned making a different cut when they got to my uterus. I’m now 10 weeks pregnant and my doctor says it is very possible to have a VBAC depending on my c-section report from last year. I’m nervous because I threw out my discharge papers long ago and I cannot remember everything about that day. What are the chances the doctors made a vertical incision when they got to my uterus. I really would like nothing more than to deliver my last child naturally. A c-section is awful, it was terrifying for me and to say the recovery was excruciating would be an understatement.