On a "light note", keep your legs crossed! "No you're not"; "Not b....y likely" or words to that effect usually have the desired effect! A slap in the b......s also cools the ardour! (Sorry, that was rather "tongue in cheek", but amusing, nonetheless).
On a serious note, like yourself, I have never fancied IUD's - a couple of friends got nasty infections/side effects with them. There are so many birth control pills on the market that it is difficult to know where to start. Have you got any close female family members or friends that you can ask what pill they have taken or taking, and, what, if any, side effects they have had or are experiencing?
Where do you get your pill from; Family Planning Clinic, doctor? Make an appointment to discuss your problems; concerns etc. They should be able to suggest alternatives that may suit you better. I've never had it, but what about the contraceptive injection - my best friends' daughter has it, and swears it's the best form of contraception she's ever had. She's a similar age to you and has been having the injection for 2 - 3 years now. At an age where weight gain and spots/acne breakout would be most expected, i.e. teenage years, she didn't suffer any more than usual - the usual "spots" that appear on the morning before a big date! The "why do I look fat in this", and "I hate everybody" moods
How does your boyfriend feel about him taking the responsibility for birth control - and I don't mean the "withdrawal method" - not a good idea - I mean "Durex" or whatever brand? Personally, I don't like those either, it's like going to bed with your socks on! Bit of a passion-killer also, I think! But, it is a suggestion worth considering whilst you are trying to find a pill that suits you - you evidently don't want to hear the "patter of tiny feet" at the present time - good for you! Talk things over with your doctor/family etc., and I hope you do find one that suits you soon. Good luck.