Is it ok to jump in anywhere on an on-going series?

For around 2 years ago I had a favourite tv-show named agents of shield that I watched the entire season 1 at then it was a pause on the show. Then I saw it aired again but with a replay of season 1. Then out of a sudden season 2 started but I didn't payed that much attention to it and thought it still was replay of season 1, I didn't realized it wasn't a replay until around the end and I didn't want to jump in to it, then it was forgotten for a long time and I just recently discovered that season 3 episode 3 and 4 will air tonight, I don't know if I should jump in or not, I'm halfway like I shouldn't but halfway curious about what is comming up next. So what should I do? As of moment I wrote this I have 3 hours and 54 minutes to decide!