OPKs suggest a surge within next 24-36 hours so they predict ovulation. Therefore you are in the middle/towards the end of your fertile window. Defo time to DTD!
I track my temperature with a 'baby mad' bbt thermometer, £5 on Amazon but free postage on eBay! Once you get the temperature shift, you will have ovulated the day before. Therefore once you have got the higher temps, i DTD just in case that day but chances are you're too late for that month.
The idea is, within a couple of months, if regular both should match up and you'll know when your best chance is. I temp so that I know ov has definitely happened as not sure I'd ever give up!
The temperature shift will stay high throughout your luteal phase, which is normally 10-16 days from ov, until AF. Some women's temperature drops noticeably just befor AF; however mine seems to stay higher for first day AF?
If you were pregnant it would remain high, and sometimes go higher still; however this would not confirm pregnancy any earlier as the higher temperature must be more than 2 weeks to suggest pregnancy, by which time AF is due/late anyway.
Sadly I have learnt there is no way of early confirmation of pregnancy; you just have to wait until AF is late. Last month I had implantation dip on BBT, perfect spotting 8-9 DPO (never spot) and some other nice symptoms but AF still turned up 15dpo :-(.