Plan B, is it normal to feel this bad?

Hey, so me and my partner had unprotected sex not too long ago ( this being my first time having sex) and we didn’t use a condom, since we went for round two I thought that it’s probably best to get plan b as a precaution. So on the 7/2/21 I got EllaOne given to me by my chemist and i took it that day. Come to day 2 I’m still feeling normal just slight little headaches. Come day 3 and I literally can’t move without having agonising throbbing pains in my head and feeling sick everytime I try to get up, so I spent all of that day in bed. Day 4 I was hoping to feel better but I wasn’t, my head was killing me and I still couldn’t get up without feeling like I was going to fall, trying to sit straight has never been any more of a task. So I spent day 4 staying in bed. Now I don’t know if it’s because I spent 2 full days in bed but come day 5 I can move around but it takes me a lot longer as there’s an initial throbbing pain in my head and my eyes go purple but after that goes away I can make my way slowly. Although I can’t stand up for so long I can at least move.

Just wondering if that’s a normal experience with plan B or if I should have phoned my chemist :(