So this is part AITAH, part what is a good action/solution here. I live in a 3rd floor studio apartment with 2 cats and have been here for about a year and a half. Leases start in August and since we’re in March I can assume the person below me has either been here as long as I have been here or just got here in August. I have not been doing anything differently but suddenly I’ve had two people (who I assume live together below me) approach me with noise complaints. The first time was in March when a girl came up and told me to keep it down. I had friends over and it was about 10:30 pm on a Monday and while I didn’t ask what floor/room she lived in, the language she used implied she lived on the 2nd floor and most likely in the unit below me with her boyfriend. She came up, knocked and told me “I don’t care what you’re doing up here but we’re trying to unwind after a long day and you're stomping" and she sounded very snarky/angry. I said I'm sorry I had friends over and we’d keep it down. I kept it short because I was kind of rattled because this has never happened before and other than one of my friends throwing a bag on the floor earlier, at the time the girl came up everyone was sitting and talking. The second time was Saturday night when we’d had a thunderstorm and tornado warnings in my area. A guy knocked on my door at around 1:30/2 am. I had been walking around folding and putting away laundry with headphones on and would not have even noticed someone at my door had my cats not freaked out because of the knocking (I didn’t hear it but based on the cats’ reaction he was probably knocking pretty hard). I checked my peephole and saw a man turn away from my door, walk down the hall and heard the door to the stairs slam. Based on the March incident I’m assuming this is the boyfriend of the girl who came up last time. I don’t like causing problems but I also don’t know what to do because I’ve never had any problems before this. I’m also really confused why a night of bad weather is when you’d come up to give me a noise complaint (granted this is me assuming that's why he was here since I didn’t actually talk to the guy) since I didn't think I was doing anything loud. I know being a downstairs neighbor sucks but I've never had any complaints from them before this or gotten any notes or anything (and if they are new the previous tenant also didn't have any issues with me). The incident in March made sense but now I’m paranoid about moving around my apartment at night or doing my normal routines. AITAH and what would be the best way to go about this?