differences in bottles of depo-test?

[e4me]

I had almost finished one bottle of depo-test and started another. While on the first bottle I had a lot of soreness especially around the injection site and a bunch of other sides. I started the second bottle and it seemed the sides were going away. I noticed that there was about a dose left in the first bottle and decided to use it up. I took it and the side effects I had earlier came back like clockwork.

Was...Is there a difference in bottles? (the lables were the same) Why would the sides go away then return with a dose from the other bottle?

Any ideas?