Three weeks in is squarely inside the window where adapalene commonly looks worse before it looks better — the OTC Drug Facts label itself says acne "may appear to worsen" at first and that irritation lessens after about four weeks, and the pivotal trials measured results at 12 weeks (https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=e6380880-5299-0826-e053-2a95a90a1942&type=display).
The useful heuristic: a purge from a turnover-accelerating active tends to show up where you normally break out and clears faster than a regular breakout. Yours showing up on the cheeks — new territory for you — is worth watching, because that pattern can also be plain irritation. The tells for irritation are itching, stinging, burning, or rash-like redness rather than ordinary pimples.
Practical plan: drop to every other night, use a pea-sized amount for the whole face, and buffer with moisturizer before or after — that doesn't blunt the retinoid's effect (https://www.dermatologytimes.com/view/-open-sandwich-moisturization-regimen-does-not-affect-bioactivity-of-retinols-and-retinoids). Give it the full 8–12 weeks the evidence is based on before judging (the AAD's general acne guidance is 6–8 weeks minimum for any product: https://www.aad.org/public/diseases/acne/skin-care/habits-stop). If the bumps itch, hurt, or keep spreading past week six, stop and have a dermatologist look — that's not giving up, it's just getting the diagnosis checked.