Yes, if you flexed during the insertion of the needle, expect it to hurt for a few days. Keep massaging the site hard. If you didn't do anything crazy with the needle or your steroids than I don't see how you would have gotten an infection from your 5th shot from that bottle.
If it gets worse then I would look at going to the doctor. I have never had an abcess so I don't really know the symptoms. If you do have one, they will have to lance the top of it and hopefully get out the infection that way. Otherwise they may have to surgically remove it if it is too deep down.
So did it not hurt at all from Tue to Thu? Kind of weird that it would start hurting just now. Keep rubbing it every few minutes when you think about and hopefully you will be fine. When I did winstrol it would give me little lumps for a few days that I would have to rub out. But with Test being an oil that doesn't crystalize like winstrol, I would not think that is what is happening.
Can always pm some of the mods that have more years of experience if you are still worried by saturday.