It takes the average couple a full year to conceive so a few times trying is not a good test to fertility. I think she was asking if your periods are consistent because that is key to pregnancy. And with young people, they aren't always. You also describe periods or menstrual cycles outside of normal. 7 days or less is normal. If you are bleeding longer, that's something to talk to your doctor about. Unless you are counting the spotting before your period and spotting as your period ends. That's not true bleeding. Anything brown on a pad or tampon is old blood and not current period. A menstrual cycle tracker is helpful. Do you have one of those on your phone?
I think 19 is too young to try to get pregnant. You got married? Sorry I don't want to offend you but how long have you been trying to get pregnant. If it is more than a year you can try approaching your GP and ask for advice. Most likely your GP will ask you to keep on trying first but at least you will be monitored.