Terry was due to undergo a scan on Thursday after coming off an hour into Wednesday night's Champions League quarter-final second leg against Benfica.
The 31-year-old suffered the injury in last Tuesday's first-leg victory in Lisbon and was able to complete that match and play 90 minutes of Saturday's Premier League win over Aston Villa.
He admitted he was gasping for air last night, but insisted he was ready to continue playing through the pain during what is a nightmare run of eight games in just 26 days, including Champions League and FA Cup semi-finals against Barcelona and Tottenham respectively.
He said after the 2-1 win over Benfica at Stamford Bridge: "I couldn't breathe and my chest was closing up. I was having a difficult time out there, especially in the first half. Hopefully, I'll be okay.
"I don't know how long I'll be out. I will have a scan in the morning and we will see where we go from there. It's just horrible. When you get one in the ribs, you can't do anything about it, you can't treat it, you just have let it heal, but I can get through games definitely.
"I thought it was okay but, later in the second half, it just seemed to be getting worse and I was struggling to breathe to be honest. It was difficult. I have never felt anything like that before."