Confused over how many weeks I am

Sa

Hello, I have 3 apps going on my phone to see how far along I am. This one says 6 weeks 3 days, other 6 weeks 6 days and one more 7 weeks 1 day. My last period date was 11th feb but my cycle length is 22 days not 28. Another website said I’m 5 weeks, I’m very confused. I want to pay for a private scan early but only for 8 weeks. Thank you in advance to anyone that can help xx