How would it collect any location data in airplane mode: WiFi, Bluetooth, GPS, and related, should all be turned off. NFC too I presume. I doubt readings from vibration (step counting), barometer, compass, if your device takes such readings, are going to be useful enough on their own to provide a good location fix.
Maybe if you take a photo of something recognisable they could log your location at that point if the photo is automatically tagged when you connect later. Though even if that is the case, I expect the OP wasn't taking pictures of any landmarks during a journey to/from the abortion clinic.
I believe the premise is that airplane mode disconnects the OS from the modem, but it doesn't necessarily turn the modem itself off. It's still hitting cell towers and phoning back to Qualcomm. If Qualcomm has this information, three letter agencies have this information.
Accelerometer and gyroscope are enough to do a pretty decent mapping of indoor locations without GPS and the like. Its all differential, so the longer it goes without a point of reference the lower the confidence is, but its possible.
Maybe if you take a photo of something recognisable they could log your location at that point if the photo is automatically tagged when you connect later. Though even if that is the case, I expect the OP wasn't taking pictures of any landmarks during a journey to/from the abortion clinic.