Tsp from 2008

Hello, I'm pretty sure I opened a tsp during basic in 2008 fast forward to now and I've been out for quite a while but forgot about all my stuff.

I know the tsp site uses a new method to log in but when I put my information in it says no match found. I'm pretty sure I was contributing, do I just call them and see if I have an old account with them?

Thanks.