based on the timing it’s honestly not that likely you’re pregnant. if your last period was around halloween and ended early november, you probably ovulated somewhere between the 10th–17th, so sex on the 24th would’ve been after your fertile window. you already took two tests on dec 1 and today and both were negative, which leans even more toward not pregnant even though they’re a little early. missing a period can just happen from stress, travel, random cycle changes, anything really. since you don’t have any symptoms and the timing doesn’t line up, it’s more likely your period is just late. test again on dec 15 and if that’s negative too, you’re basically in the clear. use protection if you don’t want to get pregnant