Swelling of gums is a very common thing and can tempoarily occur in any individuals mouth .You just need to care of ur oral hygiene .

Brush and floss daily.Remember to rinse ur mouth after every meal.Brush carefully and very gently in the area of gum swelling and do not abrade that area.

Visit ur dentist and get a thorough clinical checkup done to diagnose the exact cause of the condition and undergo treatment accordingly .

You can also go for cleaning of teeth  by ur dentist and remember to use wam saline rinses as it provide a lot of relief from swelling and it is nothing like mouth cancer  so dont worry ............for more info refer the link..................http://www.identalhub.com/dental-home-remedies-for-gingivitis-691.aspx