Random bleeding..

Hi ladies,
I had my period as per usual at the beginning of the month but 11 days later, about half way through my cycle I started having random bleeding.. It acted like a period and lasted 5 days which is normally how long my period is. 
I am currently on the pill and have been for sometime, however the past 4 weeks I have been unable to take it due to other reasons. I started to re-take the pill right after my first scheduled period but stopped when the unexpected period arrived halfway through my cycle. 
I have done some googling and found that my body could have been having withdrawals from the pill or I've just stuffed up my system with not being able to take it for a while and then going back on it..
Can anyone relate or give advice or an explanation for this? 
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