Bleeding inbetween periods whilst on the pill

Patient: I’ve been on the pill for about 5 years and never had a problem, never missed a pill or anything.Started spotting last tuesday and im only in the middle of my packet.I take the pill at the same time every day.Could it just be because i’ve started a new job so my body is adjusting or could it be something serious?I have never had spotting or any other problems with the pill.