Gonna have sex soon after 6 months of abstinence. Tips?

My UTIs are sex induced. Last time i had sex, i had blood in urine for the first time ever.

1)Can I take cranberry (36mg PAC) twice the same day? (Once in the morning and then immediately after sex at night?)

2. I do have nitrofurantoin that i never use. Can i take one pill after sex “just in case”?

3. any other tips?