IPad Pro, 11” won’t charge

I bought a renewed IPad Pro a few months ago and has been working perfectly fine since then. But recently, when I have tried to charge it, it just wouldn’t. I charge it usually once it’s completely dead and try not to use it until it’s fully charged. It had charged fine when it was on a few moments ago but when it was dead, it suddenly just started blinking the logo that it was charging. I tested all the outlets and the box worked for my IPhone, so it was either the charger or my IPad. My stepmom used to work at Cellcom and tried everything, but eventually just tried her charger. It worked fine. I figured the charger I had received from the company I ordered the IPad from had given me a damaged one. A week later with a new charger (not an official Apple charger), I plugged it in and went to bed, but it didn’t charge at all when I woke up. I then found it blinking it again as if the power was coming in waves. The port doesn’t look dirty or damaged on either so I have no idea what to do. It charges fine once on, should I take it in (I would prefer not to, I don’t have much money at the moment and don’t want to burden my parents.) Thank you

Grace