im not even sure if its female or male but my gold fish is fatter than it was and i dont over feed it.And my teacher gave it to me and if it is pregnant do I need to get a male?

And theres lots of little bubbles at the top of the bowl and it likes to be around the fake plants

Goldfish become egg-laden and not pregnant technically. Goldfish require a male and a female to be present together to lay fertile eggs. Females that are alone rarely lay eggs although I've seen proof of at least one case where a female did lay eggs when alone. They were, of course, infertile. Goldfish normally aren't mature enough to spawn until over 3 or 4 inches long. Since you have yours in a bowl, I'm guessing it's not that big. Even if it were, female goldfish, when egg-laden, only become a little larger and not profoundly fat.

I have a section on my site entitled, "Why is my fish fat?" at http://www.fishpondinfo.com/health4.htm#fat
If your goldfish is really fat, it probably has dropsy which is not a good thing to have. See this new page on my site for a general and a bacterial treatment:
http://www.fishpondinfo.com/fishcare/treat.htm
That page should give you some ideas.

The bubbles on the bowl are probably DOC (dissolved organic carbon/compounds) which is foam created from the oils in fish food and from the fish itself (body and waste). If the bowl has no filtration and aeration, the DOC can get bad and impede air exchange at the surface which makes fish mouth the surface. I suggest getting a tank for the goldfish if you can.

I hope the fish is okay (and doesn't have dropsy). If you don't understand the things I've said here, ask, and I'll provide more details.