When your cycle is irregular, when do you test?

I went off bc in feb. No periods while on it for 3years. Was very regular before I went on it. Got a surprise AF on March 12. Heavy for 5 days. No period in April but surprise pos opk on April 21st. Then what looked like implantation bleeding from April 27th-28th. (Pink cm, and then brown streaked cm). I caved and took a test at 9dpo yesterday. Bfn. Glow is telling me my period should start on the 4th, this Sunday. But another app is saying that I will ovulate next week. I don't want to waste any more preg tests. When do you test when you're irregular? The tww and never knowing when I'm supposed to start or not is killing me.