This is an open forum, should it not be best that all advice is kept on open forum rather than private messaging..?? By your own admission this is your first cycle, you are 4 weeks in.. Dependant on your choice of injection timings I might conclude you have pinned 4-8 times, less the number of times you say your mate has actually pinned for you..
This is not a lot of experience on such a serious subjects that you should be giving advice in private...
There are some on this forum with over 30 years experience in self-administering anabolic compounds (injectable and oral) myself included, I'm sure we would be more than happy to answer any questions and concerns in public for everyone to share..
I might add putting your finger over the injection site after pinning might not be the best course of action due to sterility issues, if you have to rub it (which on some forums is not recommended) then use a sterile swab.... Maybe wipe lightly if any blood or oil is present but hard rubbing is not now recommended...