how safe is this method?

I always use the condom+ early pull out method, which means that he never finishes off inside me, even if I'm not ovulating. I am 17, and my period are probably 8/10 times regular at around 30 days with a +- of 3 days. However, yesterday, I had sex with the condom+ early pull out method again. I bled slightly during the sex (10 in the morning) then continued bleeding mildly until the next day (I think it's stopping, 1pm now). It looks like the start of my period, the Colour is something like menstrual blood red. No cramps, no sore boobs. But loads of bloating. It's only day 22 today. What's happening? Could it be implantation? I used the same method on day 13, which is the day I assumed I ovulated as I saw egg white CM. The blood is enough to fill a small pantyliner. I spotted a little uterine lining too. I always check the condoms after using by filling it with water. It never once broke.