Is it possible to have gotten bitten on sat and for the bites to appear on the following tuesday? i am worried that these may not be mosquito bites.

Possible but unusual: Wise to question the long time interval. Bite reactions are generally a direct or indirect inflammatory response to chemicals injected. Itching, swelling can occur immediately or be delayed as much as 24-48 hr; beyond that is uncommon (unless itching was followed by scratching, followed by secondary reaction / infection). Besides timing, diagnostic clues incl pattern, color, location/distribution