Someone PLS HELP ME.

Destiny • I`m 23 living in London TTC baby #1
Hi ladies 
​Ok, so I starting using the opk on 27/07/14 and I got a positive result. Do then I took the opk again the next say and it was faint and and I took it for the next day 2 days and there was a faint line but I had to look closely in order to actually the line. So I stopped  taking it until this morning 04/08/14 and there a a clear faint line it was almost the same as the second line but a little fainter. 
​I'm just wondering what that's possible, am about to ovulate again or what's going on? I'm confused, lol I know I can't ovulate twice a month but I'm really confused. I've taken a hpt and it's negative, my AF is due 12th August and my last AF was 15th August and I should have ovulated 29th July but I got a positive opk on 27th.
​I'm still confused about the opk I took this morning the line was almost the same as the control line. 
​As anyone come across anything like that before?
​Any advice?
​Thanks in advance xx