Missed period on implant

I've had the implant for a year now, I skipped a period in Jan but have had pretty regular periods each month since then, except for this month. My app says i'm 2 days late and I know the implant causes irregualr periods but I can't help but worry. I had sex 2 weeks ago and he pulled out before he finished but today I've been feeling sick and noticed some white discharge(not much).I'm just worried that I could be pregnant is it normal to skipoe stop a period but still have symptoms?