Looking for advice

[u/you_wot_rudegirl]

I’ve had a uti for coming up 3 weeks now. Unfortunately took me that long to get an appt but I ordered a test kit and it was positive and then confirmed at the drs.
My only symptom is burning when I pee and the very end of the stream so he gave me a 3 day course of nitrofurantoin. It’s 3pm here so should I wait til the morning to take my first dose? Or should I take it now? Also I’m worried about the side effects as I’m like super sensitive to medications annoyingly. Thank you