Sensitivity of HPTs vs OPKs

[finnegansmom]

Hi, Sort of a random question...

I am about 20 days passed a miscarriage at 12 weeks. The baby measured a perfect 10 weeks BTW at 12 weeks. I ended up having a D&C since the baby passed a few weeks prior to that and I couldn't deal any longer. I never cramped or spotted or anything...

Anyways, I'm still spotting (brown, tmi, sorry) off and on and have been getting BFPs on pregnancy tests. My midwife and OB did not ever do a HCG count so I have no idea what my levels were at any point during this pregnancy or at the time of the D&C. And they are not going to check them at my recheck next month.

Now today, because I'm bored and so anxious to start ovulating again, I took a IC HPT and got a faint positive (not a squinter or anything you need photoshop to see... it's totally visible). BUT I got a negative on my OPK. What the heck? Does that mean my HCG is below the threshold of LH yet above the sensitivity of hcg for the HPT? It was a clear negative OPK. They both were ICs. The result line on the OPK is barely visible at all...much lighter than the HPT.

And for the record I used an cheapie OPK at 14DPO with this pregnancy because I didn't have any HPTs and got the darkest positive I have ever seen...

[MaerynPearl]

LH surge is indicated by LH levels higher than 20 miU

if you have an hpt that detects at 15miU (my saveontests.com ones were that sensitive) you would get a positive on the HPT but not the OPK which likely doesnt even test at 20miU but slightly higher (as 20 is borderline but Ive seen ladies who get their LH actually tested who say theirs is in the 50s range)

[finnegansmom]

OK thanks. So it's safe to say my hcg is under 50? at the max...
which is fine, I wish it was 0 but oh well.
Thanks!