Please can someone advise!!! Read on!!!

I took a easy at home 10MIU test this morning and there was nothing there....I did another test 12hrs later on a 6 hr hold that is a 20MIU and put the test in my bag as I was out....I took the pic 1.5hrs later and was positive!!!!! I then came home and took a easy at home 10Miu 2.5hrs later after a 30 Min hold and that was negative! It's probably a dodgy test right? Thanks!