Please can someone help interpret my chart

[teacherspets]

I had a bbt drop three days ago...no period. Being pregnant would be a disaster and thankfully is highly unlikely but what's going on?

How reliable are your open circle tempatures? There’s a lot of them so it’s difficult to tell how accurate your chart pattern is without knowing why these are open circles (and why a recent temp has been disregarded).

Is your period late? If I ignore the open circle temps the pattern looks as though your period is on the way. Ovulation could have been later than the chart suggests - the two open circle temps around o could be inaccurate and have thrown the chart into thinking ovulation was earlier than it actually was

I presume accurate as I do it first thing in the morning. Occasionally I get up in the night for a wee. I've been headachey for days but nothing. I've just sent dh to Tesco for a test. Natural cycles and FF say af should have come yesterday so I need to rule it out in my head.