It depends on her personality and history. I had a guy tell me he loved me fairly early on... I got a bit freaked. Not b/c I didn't care for him but b/c I was not too long out of another relationship and the ex was still clinging. Icky feeling love sometimes is, skywalker.
Relax, be yourself. Some women are skittish fillies for reasons nothing to do with you, but them. Assuming she's into you, and I haven't really read anything that says not, patience is the key to winning her over.
Second thoughts can generally be amended with judicious action; injudicious actions can seldom be recovered with second thoughts.
--Cyteen by C.J.Cherryh