question

On Sunday/Monday night, August 3rd, my partner and I had sex. I usually get my period on Thursday/Friday, but this time it's different. Yesterday (Friday), I suddenly lost some brown blood out of nowhere, and then nothing more... except when wiping after peeing. Now on Saturday, I'm losing some blood again, also brown, and occasionally a 'clot'. I've had a nagging feeling in my belly since Wednesday, and my appetite is way lower. I also feel very warm at night and have a gurgling stomach. What could this be? And can I take a test this soon?