shaving wrong?

so i shaved my legs this morning before i went to the lake to swim. whenever i shave my legs i do notice that i have lots of red bumps all over my legs, i'm assuming because of irritation. but like it was especially bad after i swam today, and i was just wondering if anyone else has this problem. it feels very unattractive so i'd also like to know, does this say something about the way i'm shaving? (i can only afford like super cheap equate shaving cream and disposable razors, so might that be part of the problem?) thanks!