Unscheduled bleeding on Slynd

*Just to preface, the NP who prescribed the pill for me has said to just keep taking it as normal and everything should be fine, but I’m looking for more info*

I’ve already googled so much and can’t really find the answer to my question, so I thought I’d try here. I’m taking Slynd (mini pill/progesterone only pill). I’m on my second pack, about halfway through, and haven’t had my period/withdrawal bleeding during the green pills, only mid pack for the last two packs I’ve been on (on day 2 of my period and week 2 day 5 of my pill pack).

Is this an indicator that this pill doesn’t work for me? Has anyone else had this experience on the mini pill? This is the only hormonal birth control I’ve used that doesn’t have awful side effects for me so I’d be so disappointed to have to switch.