If your chick used to have a comb and somehow lost it (injury, frostbite, etc.) it will not grow back.
If it never had a comb, I wouldn't worry too much. There are lots and lots of different kinds of chicken combs in all different shapes and sizes. I had one chick that looked like she had no comb until almost 9 months old and now she has a tiny little pea comb. Females combs don't develop too much until they are at point of lay with certain comb types being more prominent than others.
Do you know what kind of chicken it is? That may give a clue too.
This drawing I found online shows just how different various types of combs can be in size and shape.
Good news is that at this point, you probably have a female! It will be interesting to see how she grows up. Once the comb (however big or small it may be) appears, you will know she is getting ready to lay an egg.