mirena experiences ?

Brittany • Our baby boy born July 2016 💙 Our angel baby was taken Oct 2018 💔 Our Rainbow baby girl born Aug 2019 🌈 Currently TTC 2022
I got Mirena placed on Sept 8 2016. My Dr keeps telling me to just give it more time to adjust. But I have had different levels and colors of bleeding for 6 months now. Some days heavy. Some days just spotting. Ranges from bright red to dark brown. Having sex makes me bleed heavier for a week. also have random cramps, or like abd sharp twinges. Has anyone had an experience like this? I'm afraid it's not working and I'll get pregnant with it in?