Am I able to have children ?

Hello im 23 and I have been trying to conceive since i got married at 16 years old thats seven long years and my period is so weird it could be off by just a week or on time for 3-4 months or i could miss it dor 3-7 months its so weird and I havent been able to afford the testing to see whats wrong with me its just so expensive and my period also varies how long it lasts my last period lasted 4 days but they usually last 6-7 and i could spot in between periods its just so weird but i did take the free consultation with the doctor he said to him it sounds like PCOS but i dont know what to believe i fear i will never get pregnant and i get depressed when i see people all happy with their children