Should I get a career or get pregnant? Please Read Description

I am 15 years old and I have issues with my period which is a long story so I won't bother you with that anyway since I can remember the most important thing in my life has always been having children. I am roughly 320lbs and the doctors have told me I may be infertile and even if I am not my polycystic ovaries may worsen to the point where I may not be able to have children, the doctor has recommended that if I want children I should start early. The thing is I want to have children but I had this dream of having an amazing job which I loved and even if I was a single mother I would be able to support the child, what am I supposed to do if I have to start early, I am not even in 6th form yet! Please help me what should I do? Start trying for a baby around 18-19 like the doctor recommended or wait and risk not having them at all?
P.S. If I can't carry the child I don't think it will be the same for me, I want the whole package to me a mummy, please help me I feel like my life has been thrown into the toilet.

There you go again, with your half-empty cup. :-)

Your life is not in the toilet. You can be a mom even if you can't bear children. The world is full of children that desperately need caring parents. You can have a career THEN have (birth or adopt) children or you can have a career AND children at the same time. Either way, it's necessary to have salable skills that will help you take care of them. You never know what life will throw at you. I would suggest getting the skills and when the time comes that you can care for them, make the decision then based on your fertility evaluation. With all due respect to your doctor, predicting fertility far in the future isn't an exact science.

I have 5 degrees, a demanding career, a husband, and we just adopted 2 kids. I met my husband in my late 20s, and we just got married. I'm 34. As long as you're not dead yet, there's time. :-)

With all due respect to your doctor, get a second opinion. Has he not suggested harvesting your eggs for later? Has he not presented other options?