40f vaxd and mono boosted. faint positive on covid at home rapid test day 11. symptoms have improved but are not gone. fever free for 72+ hours but sometimes have chills. still have extreme fatigue, cough, nausea, diarrhea. still contagious?

Typically, after 11 days you are not considered contagious. But, if your symptoms, including cough and diarrhea, are due to Covid, then you may still be contagious. You certainly should not be going to work yet until your symptoms are improved. It is possible your test was more strongly positive later than the test you refer to so you may not be 11 days out. Call your doctor if symptoms not better

The positive test after 7 days is due to the remnant of dead viruses which are not transmitting the disease. After 10 days you are absolutely not a host who can transmit the disease although you are not completely recovered. Good luck for a full recovery soon.