does anyone else get headaches after swimming laps in a pool?

Have fun with the journey! 

How quickly does the headache go away? 

It could be the chlorine.  Do you have either a runny or stuffy nose (that's usually the first symptom)?  In my case, the first time or two I swim in a pool, my sinuses go nuts.  After a couple swims, they settle down.  I had two pools I would swim at, and as long as I swam mainly at one (or the other) I was OK, but suffered every switch.  These headaches often last hours. 

It could be breathing.  I have the most confidence in this based on experience.  You are either not breathing enough, or holding your breath.  Your breathing should be steady and controlled, exhaling until you turn your head to get a quick breath.  I tell people to hum as that forces the exhale through your nose so you don't get as much water in it.  Breathing headaches probably dissipate in an hour or so as your body works out all the excess carbon dioxide. 

It could be dehydration.  You're swimming in a hot environment, and you won't necessarily notice the sweat, and you won't usually feel overheated like you might running/riding, but it still happens.  Dehydration headaches will last as long as the dehydration lasts and if it goes away as you drink throughout the day, that may be the cause. 

Less likely causes?  Goggles too tight or pressing on your sinus cavities (suction should hold them in place, not the strap).  What is the tint on the goggles?  If they're clear or very light, it could be sunlight based (it sounds like an outdoor pool) particularly if you're good about wearing sunglasses other times when you're outside.  Are you hungry?  I usually have a granola bar or something after I swim because I get very hungry. 

I started using a scuba mask to swim in as I do not like nose clips. Sealing off my nose works wonders. No more headaches or stuffiness for days after a swim. I think the headaches start with sinus irritation, but become migranes. Mine are one sided (always on the right)  and can last for 3 days.  Oddly, I've found that a heaping dose of benadryl really helps when I do get one. Unfortunately, it puts me out for about 8 hours.

I am going to add something I found.  If I have not swum for awhile and jump right back into longer distances, I get tired and sloppy.  When I get sloppy I tend to lift my head more as I am breathing.  I breathe on one side 90% of the time.  Then I get a headache, I figured it was from poor form and poor fitness.  Plus I tell myself it’s another reason to work on bilateral breathing.

Not really sure, just my own thoughts