What kind of reaction did you have? Birth control pills and especially plan B can make women feel like they have the stomach flu. It's a reaction to the high doses of hormones and works in the same way as pregnant women with morning sickness. I've known a handful of women who can't take them because they just make them feel too sick. There are a higher risk of blood clots, yes, but they are rare. I've never heard of anyone being "under a doctor's care" while starting on birth control pills. They give you the prescription at your appointment and that's it. They don't check up on you, there are no blood level tests. You get the pill and that's it. Exactly as it would be if it were over the counter. There's nothing a doctor tells you about them that your pharmacist at the drug store or a label on the package couldn't.
Tylenol is one of the most benign drugs you can take and absolutely belongs over the counter, but you can destroy your liver if you overdose. Many more people will die from Tylenol than they ever could from birth control pills. Make it over the counter with appropriate warnings on the label about possible side effects.
I had a variety of reactions, some of which are complex and totally anomalous to medical science (which makes it difficult for me to explain them). My reproductive organs are anomalous to medical science pretty much as a rule. So my experiences are not very useful to ascertaining a general trend. I am always an extreme out-lier.
But, some of the more common side effects I had:
1. Severe mood changes that didn't resolve with time - depression and irritability. I don't have noticeable mood changes with my normal cycle, so this was definitely BC-related.
2. Continuous bleeding for over 3 months. I have very strong iron levels, particularly for a women. But I bled to the point of anemia.
3. Weight loss. And weight loss I really couldn't afford - my weight is borderline as it is.
I was on a low-dose pill. I am very, very sensitive to hormonal changes.
Combined with my more mysterious side-effects, my doctors and I both agree that attempting to switch pills or methods was not a solution for me. I needed to stop, period. And my doctors have been furiously debating the cause of my symptoms for going on 6 years now.
I know several women who have reacted badly to hormonal birth control, or certain pills/types. This is really the main purpose of the Nuva Ring, which is the lowest dose hormonal method - to provide something for women who have unacceptably severe side effects from the pill and other hormonal methods. If someone created a product pretty much for this one niche, obviously it's not uncommon and there is demand for it.
Some of the heavier methods, like Depo, the implant, etc have very severe long-term side effects, even when they're well-tolerated. It's recommended that women not stay on Depo for more than 2 years because of this.
Getting prescribed birth control for me involved a verbal evaluation, including family history. I did go back to the doctor, because obviously I had reason to. I think this was about right.
I'm simply saying that reactions to BC are much more common than reactions to Tylenol. Even discounting myself, because of how strange my reaction was, I can still think of lots of women I know who have had bad reactions. But I can't think of a single person in all my life who's had a bad reaction to Tylenol.