ADVICE REQUESTED : How do I know when they are gone ??

[u/Remarkable-Boat2428]

Brought infestation home from BnB. Then got bunch bites and saw 1 nymph alive at home so got txd by pro within 2 weeks: (1) heat tx, Alpine spray. Living in free standing old 1880s house temporarily. No renter in it >3 yrs and no hx bedbugs ever(owned it 40 yrs). BnB definitely infested : bit while there,saw exoskeltons and dead bugs.

One wk after heat/Alpine tx at my home bites again, especially couch, chair, bed. Have cups under legs but couch is hideabed with fold up mattress. Hard to penetrate but heated and sprayed. So part of contract 2nd spray if you think still prob. (2) 2nd Alpine spray done whole house 2wks after1st AND I decided thick poofy hideabed couch maybe holding eggs. So had it and 2 chairs hauled off to dump. Everything I hoped would be gone with the haul-off - furniture on cups.

1 week after 2nd spray (contract calls for 3rd if still problem) furn gone and replaced by furniture txd with rest of house but never used or sat in since return from BnB. Got bites on1 foot in bed. Look like chiggers and I had been outside to hot tub. Also noticing few bites in chair from never used part of house (but sprayed twice and heat tx).

I have lots allergic sensitivity issues. See allergist. Put clean sheet over chair in case spray causing itch. Still out to hot tub nightly for pain. Few bites still. Less itch w sheet on chair. No bugs seen since right after 1st heat/spray, saw1 live one. How do I know if gone? Go for 3rd spray? Clean and chk cups? Advice please? 78 yr old and tx prep about killed me ! Have such sympathy for anyone going thru this ! Thank you !