I've had a rotten obstetric history with 1 ectopic, 1 stillbirth (natural birth), 2 missed abortions and 3 live births, all of which were elective caesarians( 2 placenta praevia and one transverse breech).
I understand about you wanting to try labour but at the end of the day the wellbeing of yourself and the baby MUST be your priority. The obstetrician and midwives do know what they are talking about so I would suggest you listen to them. Your uterus will have been weakened by your 2 caesarians. You may be allowed what's called a 'trial labour' to see how things progress but please don't be stubborn about insisting on a vaginal birth.
If you insisted on a vaginal birth and god forbid, anything went wrong, could you forgive yourself? I'm sorry if I am sounding harsh but I've been there. Does it really matter how your baby arrives as long as he/she is healthy?
Good luck. xx