Road trip troubles

So we took a short road trip this weekend to stay with my brother in law and his family. We're in the car driving for about 4.5 hours each way. So 4.5 on Friday and then 4.5 today to come home. Our 3 month old was perfectly fine on the way there, had a great weekend, and perfectly fine with little to no fussiness on the way home. We stopped to take breaks to get her out of her car seat so she could stretch and kick around, feed her and change her. About 15 minutes after getting home though, she went from happy baby to screaming bloody murder in about 5 seconds flat. After about a half hour of frustration trying to calm her and keep her calm my husband got her swaddled tight and she drifted off to sleep. She's definitely been a very calm happy baby for the last couple months so I just can't imagine why all of a sudden she'd be so upset. Her diaper was fresh, no rashes, temp was good, gave her gas drops and attempted burping her for a looooong time and nothing but a teeny tiny burp came out (she burps like a man and with very little effort so I don't think it was burps that were hurting her but maybe the other kind of gas?) she's exclusively breast fed and for about a month now only poops once or twice a week (which has been cleared as completely normal by her pediatrician). The last 4-5 days however, she's gone every single day, some of them being blow outs but she hasn't seemed uncomfortable at all throughout all of that. Effortless #2s, eating great, and been so smiley.

If it continues we'll of course go straight

to the pediatrician but has anyone else had a baby just go from 0 to 60 like that for no apparent reason?