Should I tell him?

( all of this is just hs drama I know / understand the mistakes I’ve made )

Wayyy back in May I got with my friends boyfriend & me & him hooked up. They’re still together & theres still quiet rumors about it but I don’t think she believes them. Come late late June I found out I was miss carrying before I even knew I was pregnant. ( that emotional mess is a whole other story ) anyways I never told him. Idk if I should have but I didn’t, he still try’s to hook up but I constantly say no ( mainly Bc I’m not ready for anything like that again ) well now the rumors r bad & im pretty sure she’s going to find out soon & me & him have been arguing more lately , & now all of a sudden I feel like he deserves to know that happened. Should I tell him or does is not matter @ this point