Welcome to HCM,
After going through your detail history, If you just fingered dry finger after wiping with tissue paper it is very unlikely to transfer sperm to her genital tract.
You said she was expecting her period in 2-3 days, then chances of pregnancy
are almost nil as ovulation takes place 14 days prior to expected period date.
Menstrual delay could be because she has taken I pill
which is hormone pill can delay period and can cause pain in abdomen.
Please wait for 1 week if there is no period .
You should get her urine pregnancy test which will guide for further action, then you can visit a Good Gynecologist for valuable help.
Please practice safe sex
as it not only protects from unwanted pregnancies also protect from sexually transmitted diseases.
Dr.Akhilesh dubey M.D.