Is blood clots during a nosebleed normal?

Hi,
Just now I had a nosebleed for around 20 minutes. It started in the middle of the night and just woke me up. It was really heavy with bright red blood until I felt something stuck to the tissue from which I then pulled it away revealing a long thick clot of blood leaving a rather large puddle in the tissue bigger than the size of about 6 50ps stacked. Immediately after this, the nose blood stopped any ideas to why I had such a clotting? Anything I need to be concerned about?

I'm not sure if this is normal... I'm under the age of 16 and had my first concussion at the age of 9 but no symptoms of nose injury, in December of '15 I had a severe concussion from a 15 pound medicine ball to the lower right side of the back of my head thrown full force, I wasn't unconscious but very dizzy and ill feeling with light sensitivity and extreme headaches.
But no nosebleed immediately, it was about a week or so after when I would get a nosebleed for about 15-30 minutes with about one occurring every two weeks. I was checked with an MRI and they found I had thick lining in my nose of some sort and over the year they have became more aggressive. I'm a cheerleader, flyer that is and being dropped is a daily. In December of '16 I was dropped again and this time from about 10 feet and falling directly on the same spot as before and blacked out with a nosebleed right after. Being its January of '17 it's been a month and I've woken up in the middle of the night spewing blood from my nose, eating breakfast I looked down and my bagel was soaked in blood and have walked up stairs and it started bleeding, and all of those were between 20-45 minutes with no clotting ....the past two times it's been awful.on the 15 I ran into the nurse the first time and it bled for an hour and a half with minimal clotting and was taken to my primary doctor after but she had no answer but an ent appointment was made. My last was the 25 and this lasted for two hours and 20 minutes with extreme blood pouring and clotting. I used three regular sized woman's tampons and an entire box of Kleenex tissues and it still bled. I pinched my nose and used ice pack. Towards the end it began to clot and the one was the size of a spaghetti can top and about half an inch thick of pure blood. It was running down the back of my throat during and I guess began clotting back there. I went to cough the blood and spit as I normally had been but this time that's when I choked on the blood clot and was rushed to er. No one exactly knows what's going on besides referrals to an ent. Does anyone have any idea of what's going on?

Should I go back to the er if I can still feel blood going down my throat even though I'm sitting straight like they told me to do? I got packing in my nose because it wouldn't stop bleeding and it continues to drip, should I go back?