Go through these in order and stop at the first one that applies. If you are reading this for someone else, answer for them.
Seek urgent assessment for a sudden pop, new weakness when pushing off, inability to stand on the toes, or a rapid change in the tendon’s shape.
Prompt review is also needed for spreading redness, marked warmth, fever, or an open wound near the tendon.
Routine follow-up is appropriate if pain interferes with normal walking, work, sleep, or exercise; keeps returning; or does not begin to improve with sensible activity changes.
Earlier review may be needed for people with diabetes, inflammatory disease, poor circulation, or a history of tendon rupture.
Follow-up visits may focus on calf strength, ankle movement, morning stiffness, walking ability, and tolerance of exercise.
Return to sport should usually be based on function rather than time alone.
Running and jumping loads are generally reintroduced in stages.
The article also says
Recovery often takes weeks to months because tendons adapt slowly.
Progress may not be steady.
Temporary symptom increases can happen when exercise or activity is advanced too quickly.
Every sign above is quoted from the sofidex article on Achilles tendinitis. If you are not sure, err upward — it is always reasonable to be checked.