What Causes A String Like Vaginal Discharge?

i recently went to the toilet, when i wiped there was a long string of discharge that i literally pulled from my vagina like a piece of string. my discharge is often thick, but never like this. there was no odour, however sometimes i do have a slight odour there. i am a woman of 20, no children, had an abortion a year ago, have been with the same partner in that time, have missed a month of my birth control pill. should i be worried? and should i visit my doctor about this?