IUD and Periods

Hello! So Ive got a question for hormonal IUD users. I’ve had the Kyleena IUD for a few weeks now. When I first got it, I had light spotting with not much color in it. After I’ve had sex a few times since having it placed, I seem to now have dark brownish spotting and it’s a little heavier. My period is due in a few days so I’m confused as to how I’ll be able to tell the difference between the spotting and actual period. Will the color be different? Bigger amount? Any advice on this would be greatly appreciated. Also, I have had some cramping the last few days (haven’t really had any since getting it put in) which makes me think my period will be here soon. Thank you in advance for your help!