Paranoid...would a company hire you full time only for a temporary project?

I was recently hired full-time direct hire for a company as a web developer.

The project im working on (just me and another dev whose worked here for several years) is about 80% complete.

My focus has been mainly on this project that's nearing completion.

I am worried they'll end my employment once this project is finished.

But I comfort myself with the thought that, they wouldn't have hired a full time employee for only a temporary project. They would've just gone with a temporary contract.

I'm still a bit concerned even though the manager has mentioned they have long term plans for me.

Should I be worried?