Can anyone help me?

Ive been using the pill (Microgynon 30) for about 8 months. I only started using it to regulate and lighten my periods recently I've gotton into a active relationship. When I started the pill I never took it properly. Sometimes id miss days or never take it at the right time. Now I'm with my boyfriend I take it every morning at 7am however, we've had unprotected sex and I've recently noticed some changes.
My period is due today but a week prior to it I've had these symptoms.
Brownish discharge.. I read online that it could be old blood from the previous period or been dislodged due to sex.
Ive had spotting but only on one day. It was one drop of red blood.
I haven't had morning sickness or tender breasts.
Now I'm starting to have a white-yellowish discharge on the day of my period.

What's the chance I'm pregnant?

Any time you have sex, protected or unprotected, you run the risk of pregnancy. This site says that the pill must be taken regularly or it is not effective against pregnancy. Microgynon 30 (ethinylestradiol and levonorgestrel) (http://www.netdoctor.co.uk/medicines/100001653.html)

It specifically discusses starting dates, skipping medication and risks.

When did you stop missing doses ? Have you been taking it regular and steady without missing for over a month before having sex ?

But even taking it perfectly, it is not 100 percent, no method is, so there is a chance if you have sex.

If you were recently missing some pills, it increases those odds

But on the other hand, missing or being late one day is not really late.