Confession..// need advice.//hella gross picture (sorry)

So my now ex boyfriend and I dated for about 9 months. We haven't been together for about 4 months for family reasons not personal. We are perfectly happy with each other and plan to get back together. But I've been keeping a secret from not only him but everyone about what happened about 6 ish 7 months ago. I never cheated or anything even close to that. That's not what this is about. But about 6-7 months ago.. I think I had a miscarriage.. Like I was maybe 3 close to 4 weeks late and I told him but we are just teenagers and think the world does what we want it to. So once I did start my period I thanked God himself. And so did he. But this period was weird. It was constant heavy flow for about 4 days. But the first day I had a clot come out that was just crazy unusual. I just now found the picture I look of it.. I don't know if I should tell him now or if it's too late. Or if it even matters at this point. I just don't have any idea of what to do. Cause like I don't know if it was one or not. And how could I even tell him something like that happened if it happened so long ago. How do I bring that up? Should I even? 
This is the picture. Sorry about it. It's pretty gross but I literally just found it again on my iPod. So it's bring all this up for me again. It was like as wide as my thumbs and as long as almost my whole hand.. I didn't tell him cause I was scared of what he would think or say or do. Should I keep this to myself or what should I say?.. 
Do you guys think it's even a miscarriage or am I overreacting?..