I had sex two weeks ago while on period. i forgot to take my pill yesterday, took two pills today. what are the chances of pregnancy?

"Zero": There are no surviving sperm from 2 weeks ago, so there is zero chance of pregnancy due to yesterday's missed birth control pill. Of course, "zero chance" is mathematically rounded off because there is always a finite although tiny chance of pregnancy when fertile people have sex (so be married, settled down, and ready for any cute surprise baby).

See below: Agree with Dr. Kwok. If you miss your period by 4-5 days, do a home pregnancy test. If the result is negative repeat the test 4-5 days later unless you get a period by then. Use first morning urine and follow the instructions for the test carefully. If you do not wish to be pregnant, use contraception all the time, every time. You may consider implanted contraceptive, or IUD. Practice safe sex if you have sex. Get HPV vaccine