pregnant but don't know how far along? ?

I went to the hospital and tested positive for pregnancy on Saturday September 9th it's now September 11th and I don't know how far along I am?? this is my first time being pregnant and I wrote in on this app my last period was July 5th (that's when it ended) my period is very Iregular sometimes I won't get it for a month. I broke my phone after that and couldn't get this app so I couldn't write down if I got my period in august but I don't remember having my period last month. on this app it says I would of had my period around the 28th of august and it says my period is 24 days late because I haven't been on here so I'm confused. help?!?!