OPKs, is his a good brand?? need advice

Lexi
Hi ladies! My hubby and I got married last week and since I don't really get my period much ever I decided I wanted to use some OPKs, is this a good brand to use? Also I'm taking metformin 500mg twice a day. Does anybody have any experiences they'd like to share or advice for us? Thank you and baby dust to all!