My period slowed down to spotting after 3 days, could I be Pregnant?

In all my 31 years my period has always been consistent and on time. Once I got my Mirena IUD, my periods stopped but once I took it out to conceive my periods went right back to normal. Until this time. I took out my IUD at the end of August and have had my period since then. Well my period always lasts about 7 days sometimes longer but this cycle I started on Sunday n it was heavy 3 days n now its practically gone! After 4 days! Never in my life has that happened and the past two nights I've felt really nauseous! Idk if its wishful thinking on my part but I am trippin' out. One of my friends had her period the whole time she was pg. So now I am thinking if that could be me? I have two children by my ex high school sweetheart and found out at 5 n 6 weeks I was pregnant with them after having a missed period. I never had my period then it go away so early. This time I finally found my forever love and idk if its cuz its a different man that it could be a different pregnancy lol I will wait til next month and see if I get my period then and look out for pg symptoms if I am pg I will be shocked because I've never had it happen this way! Any ideas if that could be it? Any of you have your period while pregnant?