Clear blue accuracy

hi all I was just wondering if any of you could put your mind to rest i got a positive test on 31st August said 1-2 weeks did another one in the morning of the 5th said 2-3 weeks. My concern is I was with having fun with this one but was seeing an ex upto 13th July and although I had a period i am unsure if was normal, so I was just wanting to see how accurate the clear blue level are as it is making my anxiety spiral 
thank you all in advance