I Agree that they don’t look like tick bites, each time you are bitten your body responds in a different way (depending on the levels of lymphocytes produced) so it’s most probably just a midge/mosquito bite but your body has responded differently to how it has in the past
That looks like the way I react to a horsefly bite. The blighters have bitten me through leggings before. If it gets much worse than that over the next few days, you may need an antibiotic as one of my bites did once. Back of knee ballooned so that I couldn't bend my leg. Sudocrem helps a bit.
Mark the perimeter of the redness so you can tell easily if is getting worse. The bite on your arm looks nasty. Might be an idea to put some savalon/bepanthen cream on it. Antihistamines, tablet or syrup in preference to cream works well for me too. I wouldn't rule out a trip to the GP either if it gets any worse.
I agree with a ring around it to monitor the size. I’d take an over the counter antihistamine too to reduce the reaction. Get it seen if it gets worse - grows, becomes itchier or the skin in that area swells a lot.