REGEXMATCH a string from the beginning of the sentence until a string:

Example: "email send 9.15, 9.17 mentee dropped 9.17"

I want to get and check if the "9.15" and "9.17" contains in the sentence before the string "dropped" using regexmatch on google sheet. Basically, I want to check if "email send 9.15, 9.17 mentee" contain "9.15" or "9.17"

I am trying to use .^(?:9.15)(?=dropped) but is not working.