My mum just had a go at me...Idk what to do!? 18?

I found out yesterday I have Polycistic ovaries. I have 22 follicles on each. I'm 18 and my fiancee is 20. When I spoke to my mum today about going on a fertility drug to make me ovulate regularly she said 'NO NO YOU CAN'T DO THAT' my fiancee and I are financially stable but she still doesn't trust me to make this decision. I'm going to my GP soon with my fiancee to get the fertililty drug but I still feel betrayed by my mum. I am young, healthy, educated and I still feel she thinks I'm too young.. Please help!?