Implanon

Hey girls I need a bit of advice and some knowledge of your experiences, I got the implanon on the 4th of december last year. A few weeks later I was due for my period but got old blood and discharge. Anyways that didn’t stop but it went very light that I thought it went away last week. I had sex last week and ever since then I have had light bleeding. And it hasn’t stopped at all. But it’s very light. Should I go to a doctor or wait a bit longer? It hasn’t even been a month and I’m worried. Please help a sister out I’m desperate. ❤️☹️