I had a similar experience. When I noticed, I just told my gal, that if she wanted to continue to look, I was okay with that, but then I should also have the same right and I would want to re-join and look also. In my chase she decided I was the one and we have been married 10 years.
This heart to heart will give her the nudge to either move on or commit and get off the site if she expects the same from you. If she does not have a problem with you re-joining so you can be of the same status as her, then there is your sign.
Good luck!