OK Please help me work this out

[Dasharity]

ok a little history,

This is my first cycle charting, started observing cm once af finished and started taking temp on cd13.
DTD on cd12 (but wasnt trying to ttc and withdrew but not sure if got out in time if not only a small amount at opening). on cd13 had huge glob of ewcm prob bout a tablespoons worth and nothing else since, cd14 had o pains, cd16 temp starts to rise then on cd18 temp drops below cover line and the rises back up on cd19, so because of this FF asumes that i have o'ed on cd18 but none of my other signs match up because i wasnt temping when i think i o'ed so could this drop actually be an implantaion dip as i have only just found out that these occour and now im really confused,

Will try and link chart and mabey some one can make more sence out of it that me
2256c4 Ovulation Charts