I thought I'd come here and give an update on my "side effects". I got the first Pfizer shot two weeks ago exactly.
The side effects were quite mild, nothing worrying. I got my shot at 12pm (didn't feel the needle at all). No immediate effects until 6/7pm, my arm started hurting a bit (it wasn't pain per se, just felt very heavy). This lasted all night and into the following morning. By 11am the following morning, my arm pain/heaviness had dissipated. I felt nauseous and slightly tired for two days after that, then all went back to normal.
Some advised heavier period/intense cramping after the vaccine. Here's my experience:
I had my period on time (today) with some cramping. I normally don't have cramps unless I consume dairy or have fizzy drinks (which I did consume in the last few days). Plus, I went for a run this morning which seemed the have exacerbated the pain as when the period started originally there was no cramping. I can't therefore confirm if the cramping is related to the vaccine or my food intake or running. The cramps didn't last long though, about one hour. I normally don't take Nurofen, but I did and they just went away immediately. My period isn't particularly heavier than normal either. As far as PMS goes, nothing specific. My PMS was actually a bit better this month (aside from the exhaustion, but that's every month).