Allergic to chlorine, had a bad reaction last night because the levels were high. not feeling well todsy as a result. should i avoid the pool today?

Probably a good idea: If you are having allergy symptoms and need to take medication for them, it is not a good idea to go swimming. It is also better to decrease your exposure to the chlorine until your symptoms resolve.

Toxic reaction?: What symptoms did you have? Skin, Respiratory, neurologic or other? If you are convinced that the chlorine was the cause then yes, wait until the water or ambient levels drop. FYI , technically speaking reactions to chlorine are not actually due to allergy.