The whole issue of currency is quite subjective, but if you are questioning it yourself then that's a very good start. I've flown with pilots who are very current and very experienced yet do some very strange things -for example starting a descent from the overhead without getting ATC clearance.
Some people will always be a danger just because of their character, whereas someone more timid may be perfectly safe although rusty just because they are cautious. My club used to have a 28 day currency rule when I started but they then increased it to 60 days which personally I find a bit too long for my own comfort. I've never had a problem during a check-ride, but it's nice to have someone sitting there 'just in case'.
There's nothing to be ahamed of in asking an instructor to sit in with you (especially if you can agree with him that you get the PIC time), but I know if you talk to some pilots they look on it as a failure doing that once you've got your PPL.
Do you what you feel comfortable with and you'll probably be fine.