HMO

hey guys, well yesterday i recieved a letter in the mail, saying that i now have an HMO plan through NJfamilycare (state insurance), im really happy about it, but what confuses me is this, just 2 days ago ironically my friend's mom mentioned to me that i should speak with someone at my docter's office about getting put on an HMO plan, and in order to do that, you have to actually go the office and apply, well i didnt have to, it came to me out of nowhere!, im thinking i got it because a week ago, my docter prescribed me a anti depressant to start taking after i ahve my son in a week or so.......it's just so weird.....anyone ever have something like this happen to them?