Opinions please?

[MummyKP]

I used up a few OPKs I had in my bathroom this week, as I was intrigued when I O. On Monday, cd12, I took one and there was a faint line, Tuesday I was unable to test because of car issues and getting home late, Wednesday I had a stronger line, but not strong enough to be a positive, then Thursday and Friday they were faint again. All tests were taken around 4pm after holding for 4 hours (maybe just under 4 on some days). Do you think I O'd on Tuesday, cd13, when I didn't do a test but got a stronger line on Wednesday? FF predicted O for today, mydays predicted for yesterday. I had some slight cramping this morning but very slight and didn't last long. Cm has been creamy/water this week, with some EWCM last weekend (not loads though). Any advice would be appreciated currently nearing end of cd17 of a 28-30 day cycle.