Need help roots coming out of drain holes

ok hey everybody my plant is a good month old thursday but the roots are coming out of the drainage holes AGAin for the 3rd time is that bad???? i know i should switch pots but i wanna know will i absolutly have to switch pots every time roots are coming out of the drainage holes or can i juss let them get root bound??? will they still grow if i let them get root bound?????

Repot Man Let Them Have Room To Grow How Big Are You Trying To Let It Get You Should Be In A 3 Gallon Al Least Do Not Let Them Go Rootbound Leggy Groth

but when ever i go to a store i can never tell which ones are the 3 gallons none of them say what size they are

Well you can do like I did and cut a 5 gal bucket off just below the handels makes pretty close to a 3 gal contaner.peace man