When should I take my son back to the ER?


My son ran a fever no greater than 101.3 yesterday (Saturday) I gave him some Motrin which lowered it to 99.5 but he seems to still have the fever. We were at the ER on the 21 due to his ear ache but four days past and now he developed the fever. Should I take him back to the ER ? Or should I try to wait it out til Monday and try to get him in to see the dr.? Don’t now what to do I’m also 39 and 4 days prego! Ugh just beyond stressed ? I need some answers mamas!!!