What is this?? Help please!!

So I posted in another group this morning and only got two responses, I need some opinions please. I have had 2 miscarriages in the past 1 1/2 years so I kinda know what it looks like. But I've been on birth control the last 6 months due to hyperthyroidism so I'm on medication trying to get my levels normal before we try for another baby. So my period was a day late and then this morning this came out when changing tampon.. do you ladies thank this could be another miscarriage?? Thank you in advance for your help..