Allergic To Pads?? HELP!!

Hellooooo Ladies!!! So basically I have been having my period for a very long time now and I’ve always used U by Kotex pads. I never had a problem with them until last year. One period in specific i got this bumpy rash closer to the back and it was burning in the shower w hot water. I thought “hmmm that’s weird maybe i was sweating in my pad and i got a rash, no big deal” last forward a couple months later it happened again but not as bad. It would happen every couple periods for about another 9 months or so but it wasn’t that bad and I didn’t even really pay attention to it. Anyways, in April (I think) I got this awful swollen SUPER itchy and red rash down there in the EXACT area of my pad it was so uncomfy I was in so much pain I couldn’t stand or sit or do anything with our wanting to carve out my area. Cold wash cloths helped but not too much. Thinking it is an allergy I switched to L. brand pads (a very natural brand) and they worked GREAT!! But now they’re starting to irritate me again but just on the edges of where the pad goes. Anyone else have this problem?? I have a couple other natural brands of pads to try but I was just curious to see if anyone else had this problem too and if there is a certain chemical or adhesive to stay away from?? L. brand pads are all natural and free of dyes, fragrances and a bunch of other stuff. Not sure what to do as this is becoming super annoying and uncomfortable. Not sure if I should see a doctor because I’m pretty sure it’s an allergy.