how to change the weeks?

Nekoo

hi, today i got USG, they told me I am 4 weeks pregnant. So I know my ovulation date (15 th June) but this app counts weeks from period. Is there any chance to change? It shows wrong sizes etc.. Like the baby was concieved in 15th not the period was in that date. If i log my period date that this app shows me I'm 6 weeks and 2 days ( last period was on 29 th may) .

😅 what to do!!!?