Am I spotting, is this a second period, or something worse?

You are probably just spotting. Birth control pills are regulating your hormones so there will always be some kind of spotting in between cycles. As far as I know as long as you don't skip pills 3 days consecutively, you should be ok and although you should take them at the same time everyday, missing a day or 2 should be ok. It could also be some old blood from your period 2 weeks ago which hasn't all finished completely. It could also be from rough sex. The placebo pills are there so you don't forget by stopping for 7 days like some other pills like Diane 35. There shouldn't be a problem to continuing with another pack too as the 7 day break and a period is not necessary, apparently the breakthrough bleeding on the pill is more for psychological reason than physical because most women want to "experience" a period every month. Spotting is normal on birth control pills as long as they are not heavy bleeding. However, if you have regular periods on the pill and you don't get your period when you should, take a pregnancy test because the pills are not a 100% protection. Also, I'd advice you to use a condom too even on the pill, this is what I learned through my volunteer work experience wt HIV education. Good luck