Spotting and late period

I had a light period (or what I believed to be my period) early February if not late January, I honestly forgot when but I’m thinking it was late January. Everything is so wonky after giving birth. It was extremely light and I had no cramps. I got another period on February 23rd-26th. This one was much heavier. I started my birth control about 3 weeks ago and I’m technically 2 days late as of today. I was suppose to start this past Monday but I’ve only been spotting. I’ve had lower backaches, headaches, irritable and cramps. I know it’s normal for things to be off after starting birth control and giving birth but I’m hoping I’m not pregnant again. I haven’t taken a test. My bf and I had unprotected sex prior to starting birth control but like I said I had gotten my period afterwards. I started my birth control on March 2nd and have taken it like clockwork since. Has this happened to anyone else? They were late for their period after starting birth control and it then it came later and they were weren’t actually pregnant? I don’t think I am and I know I can easily test but just wondering was anyone else in the same boat and if so what was your result?