Can you tell me docs, is it bad that i'm a teenager and use kids toothpaste?

No: Most of the therapeutic effect achieved in brushing is through mechanical cleaning, not chemical cleaning. Toothpaste with Fluoride may give a small advantage in anti-cariogenic and provide a clean fresh minty taste after brushing and that is all.

Toothpaste: Kid's toothpaste will offer you more flavors than their adult counterparts which are usually a variation of mint. Fluoride is the active ingredient in toothpastes as research indicates that it helps to reduce decay/cavities. A toothpaste designed for children may have a lower level of Fluoride than an adult one to reduce the potential problems that can result from swallowing it.