No period but spotting after sex???

So I take a mini pill that has stopped my period for almost a year. I get breakthrough bleeding and I know what that looks like (browny yellowish) but I know for a fact that I have been taking my pill on time for about 5 months now and have had no breakthrough…until now. This however, doesn’t look normal to me. It’s light browny pink and I’m worried cuz my and my partner had unprotected sex a little over 3 days ago and I’m thinking “implantation bleeding?” Yall please help cuz I’m nervous in the service.