Odd bug? Or Drs trip needed?

[Cakedoesntjudge]

DS (7) was sick multiple times in the night while with his dad last Saturday night. When I picked him up Sunday he was ok but got a temperature towards the end of the day and was understandably lethargic. He was fine by Monday and spent the day rushing about so was due to go back to school Tuesday.

Then Tuesday morning he was sick again but just once and was then fine. I came down with it that day and followed the same initial pattern. Since for the rest of Tuesday and Wednesday I only gave him plain food and built up the amounts gradually. I haven't felt like eating since but otherwise I'm fine.

I noticed this morning he'd developed what looked like heat rash all over his chest and back but he was otherwise ok and school said to bring him in and they'd call if there were any issues. He was there and fine all day.

Exdp has just text to say that he has been sick again! Otherwise fine and rash has disappeared. I'm finding this really odd because we presumably had the same bug and the same initial symptoms but now he seems to be fine but every couple of days just has one episode of sickness. School aren't overly happy about it because obviously, this early in the year, it's not great for his attendance. However, to be honest, I'm not overly concerned about that - if he's ill, he's ill and I'm pretty strict about following the 48 hour rule. But I'm beginning to wonder if he's developed an infection of some kind off of the back of the virus and whether he needs to see a doctor?

Not sure if it's pertinent but he's had 3 nosebleeds this week. He's gone through phases of regular nosebleeds before and the doctors have said they're probably due to his picking his nose which he swears he doesn't do but it wouldn't surprise me if he's doing it the minute my backs turned 🙄 but he's not had any in a while so these 3 out of the blue on top of this are making me wonder if I'm glossing over all this and I should be more concerned?