Confusing bleeding

Hey, I came off the pill in April and have had periods since. However when I’m due on I’ve started with brown spotting intermittently which can sometimes happen on and off for 5ish days before any real period arrives. I know you don’t count the first day until you see red blood and need to use something but at the moment I almost feel like I’m on for 2 weeks by the time I’m spotting and then actually properly bleeding. Does this mean there is a problem with me? Will this prevent me from getting pregnant? I’m really worrying and just want things to normalise now x