Looks like you O'd on CD18...you should get your crosshairs after you enter your temp in the morning! It is so gratifying to see your temp jump and KNOW for sure that you ovulated. Now on to the hard part, the 2ww!
Amoxicillin is perfectly safe, I had to go on it last cycle and my dr specifically put me on it because it is safe when ttc and when pregnant. I don't know about the others though.
As for the others wanting to start charting, you can start any time. The month I started I ended up starting to chart mid cycle and since my cycle was so long I was able to capture a couple pre-O temps so I could see my range for pre-o and post-o (check out my chart, its the oldest one). Even if you have already o'd it will give you an idea of your post-o temp range and IF AF comes this month you will be able to see how your chart reacts to it. For example my temp drops before AF ever shows her face so I know she is on her way and can prepare for it. Definitely make sure you temp at the same time each morning, and you need to have atleast 3 hours of sleep for it to be considered an accurate temp. Don't do ANYTHING before you take your temp- this includes talking, getting up out of bed, going pee, etc. First thing you need to do in the morning is stick that thermometer in your mouth and just lay still till it beeps!

I temp the entire cycle, even during AF, just to keep myself in the habit but if we go out one night and I drink during AF then I let myself slide and not temp in the morning.
**Also, drinking the night before can impact your temp--how much is dependent on the person and the amount of alcohol, but I just wanted to give you a heads up!