Hello, I'm 16, a virgin, and have a regular menstrual cycle, but my vagina opening is so covered by skin that blood flow can be slightly painful and very slow. Is this normal?

Ms.Cypher, I have moved your question to Women's Health so that you can get the appropriate advice.

Are you able to insert a tampon? Your pinkie?
Having trouble with a tampon at first is pretty normal, but having pain from slow flow I don't think is. It's possible that your pain is typical menstrual discomfort, so please describe it more. Typical might be a feeling of hot weights in your pelvis, cramping of the uterus, low back pain, and or bloating. Some women get all of them and are practically incapacitated, and others get none at all. There are many home remedies (which doctors will agree with) to help. A key one is to lie on the bed or floor and lift your pelvis up and hold it up with your hands, over and over. Heating pads, no coffee and spices, walking, the list goes on.

No, I'm not able to insert anything.
Oh no, haha I've had my fair share of period pains, trust me.
It's difficult to describe, honestly. I guess it is so difficult for the flow to be normal, that it.. gets stuck? And even sometimes blocks my urethra, causing more discomfort. I'm not sure if its normal for a virgin to have so much covered or not, but I'm concerned that it may affect my health.

You should see a gynecologist then, and be emphatic about your situation. This happens more often in cultures where girls are sewn together to create an artificially small opening, and it does create problems with menstruation and urination. It's easily fixed in an outpatient setting.