Even without ejaculation happening inside, pre-ejaculate fluid can carry enough sperm to cause pregnancy, so a period this late, over five weeks, can't be ruled out yet. Ongoing stomach pain alongside a missed period is also something a doctor needs to actively rule out, not just the pregnancy itself.
Next Steps
Take a home urine
pregnancy test now; a negative result this early doesn't fully rule out pregnancy if the pain continues. See a gynaecologist soon, since both ectopic pregnancy and a miscarriage need to be excluded given the pain and the missed period together.
Health Tips
Go to a hospital urgently if there's fainting, dizziness, one-sided pain, or heavy bleeding.