no period again!

i was diagnosed with pcos 7 years ago after several complications one being a 6month period i had a dnc and was put on metformin (glucophage) and clomid after 3 years i finally had a baby girl breastfeed her 12 months i never got a period (the doc said this could happen but no one i know) until 13months post so heavy it never stopped i was put on meds to stop it and start it once again since i have always had trouble. i was out on metformin and clomid again and 10 months later got pregnant with a baby boy that i breastfeed for 12 months as well he is now 14 and 1/2 months and still no period! i just started metformin again and yes call me greedy but i would love another baby i love children and have wanted them my whole life i didnt have my first till i was 33 and my second at 35 now i am 36 and 1/2 i am so worried my period will never reterned and my dreams will be crushed on chances of a third (i am very grateful for my 2 and thank god daily) any advice or anyone not have a period the whole pregnancy and 14 months after? when i was young i never had periods so i was labeled lucky but after years of this whos lucky :(