Sudden Side Effect to Entyvio?

After I got my two initial loading doses of Entyvio I went straight to at home pen injections. Things have been going well and my GI did a CT scan to see how things were looking. Based on the scan the UC inflammation seems to be decreasing and he thinks the Entyvio is going really well for me. I now have IBS with UC that we’re working on managing but that’s a different story..

On my last two pen injections (4th & 5th injections for me), the site around the injection has gotten severely red, swollen, and itchy. It’s a huge round inflamed area. On my previous injections, I had zero side effects. Only a little spot of blood from the shot and that was it. Has anyone else experienced sudden side effects after multiple doses?

I follow the directions for the shot to the T. I’m changing the injection site each time, my skin is always clean and wiped down with an alcohol swab. Hands are washed and I take the pen out of the fridge 30 minutes before injecting. The liquid is always the color it’s supposed be with no air bubbles. Both doses were sent in different shipments by the same specialty pharmacy.

I don’t want to change biologics, especially if my GI is seeing a decrease in inflammation but I also don’t feel like this is a normal response given the past 3 injections had zero effects. I did message my GI about the issue and am awaiting response but curious if others have experienced anything similar.