There could be latent TRPs also, that get activated after the main one is resolved. So you have to palpate the area to check of other minor TrPs and treat them .
To hopefully totally resolve a TrP fully you do the pressing and then a stretch and massage to the area.
You may have some ongoing muscle tensions that keeps reactivating that same TrP spot.
It becomes a nasty circle that has to be figured out, what is causing the muscles tension and re creating that trigger point?

Does the chiro use ultrasound, low level laser or IF stim (on a low/mild setting)?
Any of these might help with the muscle tension in the areas you mention.

Have you had any Imaging like xrays /MRIs to verify no c spine issues?

Have you found the TrP sticky thread?
http://neurotalk.psychcentral.com/thread125577.html