question about contraceptive implant

I recently had my blood pressure taken on the arm I have my implant in, hurt at the time and was abit tender for the next day or two but it's okay now. Since having my implant a year ago I normally have a period every 2-3 months but my last one was only 1 month apart, less than 2 weeks later I'm spotting again and getting cramps. Is this normal or do you think my implant could be damaged? It feels straight in my arm and it doesn't feel like it's snapped. Has anyone experienced something similar? Thank you!!!