About to fall ill

So, i’m not sick just yet but i can always tell when i’m about to be as my body does a good job of giving me a heads up.

Just before i fall sick my body tends to feels weird and i’ve woken up this morning with all the telling signs - slight tingly sensation in the body and general fatigue + throat is dry.. annnnd my HRV has dropped over the past two days. But no cough, no runny nose etc…..yet.

I’m 14 weeks out to London Marathon. Last week i ran 12 miles for my long run and today im scheduled to run 13.1 mile with next week being deload week.

Not sure whether to still do today’s run or give it a miss?

Also the “long run” during deload week is 7 miles so wondering, if i do give it a miss to run the 7 or do the 13.1 i missed this week?

FYI week after deload week my long run will be 14 miles.

Not sure what to do, don’t want to risk making it any worse than it’s about to be but also don’t want to fall behind on training either. Please advise. Thanks!