An increase from two runs to three changes frequency as well as distance. Adding hills or a fast session raises demand even if the weekly kilometres barely move. Your recent training, injury, sleep and response all matter.
Build from a level you can repeat comfortably, then change one or two demands deliberately. A simple training log of time, effort and next-day symptoms can show whether the new level is settling. If progress stalls, holding steady is still useful information.
WHEN TO GET HELP
Pain that grows, alters your stride or remains clearly worse after sessions warrants reassessment.
Further reading
This is general information, not a diagnosis or an individual rehabilitation plan. An assessment may change the advice that is right for you.