If your cycle is staying pretty consistant with 32 days. I would give the opks another try. I would start them around cd15. It is unlikely you are o'ing b4 cd17 or 18. But, cd15 is a good place to start. Bbt is another option. It will tell you once o has occurred. Just not b4. It it an excellent tool for noticing the patterns your cycle follows. It does require taking you basal temp every am b4 getting out of bed, immediately upon waking.
IUI is Intrauterine Insemination. It is when the sperm is collected and then cleaned, (the dr has monitored your cycle for when the timing is right for conception) the sperm are inserted through the cervical opening directly into the uterus via a catheter. Dpiui is "days past IUI", it is the pretty much the same as dpo. Hth! (Hope this helps)
There is a complete list of the abbreviations at the top of this page under the tab "Health Pages".
also...what is iui and pdiui?