Hi, I've Been On The Same Contraceptive Pill For 4

Hi, I've been on the same contraceptive pill for 4 years. About a year ago I came off it fot a couple of months. Since I've gone back on it, I start bleeding every month in the 3rd week of the pack. For a while now I've bled 2 weeks of every month. Before I took a break from it, I was able to take 2 packs back to back without bleeding. Is this breakthrough bleeding?