Early detection pregnancy tests?

Without wanting to get into too much detail, I am looking for reliable early detection pregnancy tests (if they exist!). I am unusually late although I have yet to miss my period for this month (i.e I’m not a week late yet). I am sexually active (in a committed relationship) so there is a chance I could be. However I really would like to find out as early as possible as I would really need to look into all my options regarding finances, housing, jobs etc if I am pregnant. N.B I’m from the UK, keep that in mind of you suggest American brands haha 🙊

Also could anyone let me know if they’ve ever experienced late periods due to diet change? I recently cut out carbs and processed food from my diet so I think this could be a reason I’m late but I don’t know anyone this happened to.

I’ve also noticed I have a lack of sore boobs and PMS cramps, just lack of change to my personality which I usually experience before my period, which has got me spooked.

Sorry if this all sounds a bit dumb I’m just really looking for some genuine help! Thank you 💕