I did not received my refund yet. I filed and accepted on FEB/05/2018. Today is March/11/2018. But IRS tracking tool says refund is still being processed. What do I do?

It depends on if you claimed a EITC, then there is a delay in those returns, due to The Path Act.  See information below:

https://ttlc.intuit.com/replies/5556415  If you feel it has been too long contact customer service at 1-800-829-1040 to see what the delay is.