HELP!! Please:) PERIODS

Hi, I'm on Alesse 28, so I have one week of placebo pills.
 I've taken them regularly for three months now; however, I skipped the placebo week for month 4. I went straight to my month 5 pills instead, because I didn't want my period this month. 
I still got it my period the second week of month 5 tho. I heard it was safe to skip my placebo week to skip my periods, but am I under some misunderstanding? Is it normal to still get your period even if you skipped the placebo pills sometimes. 
Note: the period this time round is lighter and longer.
Any advice would be appreciated!! Thank you!!