I Am 21. And I Had Sexual Contact Once. However

I am 21. And i had sexual contact once. However i have been worried about something. The opening of my vaginal feels bumpy. It's not painful or isnt uncomfortable. It's just bumpy. Not chicken skin either. I can see some outgrowths. And i am really worried if they're genital warts that might cause cancer later :O
Also i have back pain. Is it any symptom of cancer? Please help.