Hello,i Had My Last Period On 23rd Dec 2015,and It

Hello,i had my last period on 23rd Dec 2015,and it lasted for 6 days,1st 2 days were brown Lil discharge then normal bleeding.on 9th Jan I had seX (withdrawl)method.till today (3rd feb)I haven't gt my periods.but a underskin painful pimples on chin appeared.lil white discharge.i always have irregular periods(late /fast) every month.am I pregnant?