Brown spotting

Could be implantation bleeding. You can call a gynae to ask. Cos week 4 it might not be detected through the vaginal scan as well. If it’s very light brown spotting without discharge maybe no need worry too much, but have lots of rest. If it gets heavier with red blood & discharge like period flow, pls see gynae asap. There’s always kkh a&e which is 24/7.