Am I just paranoid

Last had unprotected sex on the 15th January and was late taking my pill and I keep noticing for about a week now little things just not feeling right like frequent headaches, sore boobs and cramps, more discharge than normal, bloating a lot, and just not really feeling myself. I'm also now late on my period not by much I did experience some spotting earlier last week though which I thought was a sure I sign I wasn't pregnant but after researching a little bit apparently that's normally in the first two weeks of pregnancy and I'm getting really stressed now but I have been paranoid before for no reason and spent money on tests like £11 for no reason and then I feel like I've wasted that money what would you all advise me to do?