Spotting two weeks before period

My boyfriend(25) and I(24) had protected sex last weekend. On Monday I noticed I was spotting but it wasn’t enough to fill a panty liner. I had brown spotting all week up until yesterday and this morning where now it’s pink spotting only when I wipe- again, not enough to fill a panty liner just when wiping. Today marks a week that I’ve been spotting. When i started last week- I wasn’t due for my period until another two weeks. Now I’m supposed to get mine end of next week but I’m concerned as to why this is happening. I’ve also been having lower abd cramping. I’m also on birth control… what’re the chances this could be either period related or pregnancy related……