Will a mail to the journal asking about the status of my article have a negative effect on the decision of the article? One of my journal article was submitted to a journal last year. It has been under review for more than 3 months now. I want to send them a mail asking for my article status. It is given in the website of the journal that the average time for first decision after the article goes under review is 8.5 week. Is there a chance that this mail may affect the journals decision, like they may think that I am being pushy and might just not even go through the paper and reject it?
It most likely won't. I think it is normal to push the editor if there is a significant delay. Check what the average time for receiving reviews is first.

I have done it when there has been a significant delay and it hasn't been a problem.