Can/will an OPK detect HCG?

Using clearblue digital... had a positive LH surge 4/18, had sex 4/14 thru 4/16, ovulated 4/19, spotted very lightly for a week, and got another positive LH surge just today. I have several early symptoms of pregnancy but haven't tested yet. Is it possible to get a positive on an OPK while pregnant if it is detecting HCG instead of LH? Or did I just have two separate positive LH surges within two weeks of each other?