What Are The Side Effects Of Impalanon IUD?

hi ive got a problem, i think im experiencing implantation bleeding as my period is not due for 10 days and it is like pink and brown and very light, it stops and comes back and has been like this for 2 days i had unprotected sex a few times over the last 16days is there a chance i am pregnant as i am experiencing symptoms but dont no if i am just being paranoid and how long should i wait to take a test?