Relationship advice

So me and my bf been dating for almost 2 months now. And so well my bf’s Ex hits him up this morning and so I look at his phone & it’s a Fb message from his ex. And I’m reading some old shit nothing sexual or I miss you or love you type shit. But he did tell her Goodmorning this morning and she said it back after the fact me and him just got done having sex ! Smh. So I get upset and start to feel some type of way So he’s starts explaining the situation of what went on ...But he did admit to me that he still has feelings for this girl ;but she’s not into him anymore. Should I be concerned about this y’all? Idk what too do? And he said it’s been almost a year since they actually talked !!