Ummm, I had sex throughout my chemo treatments. On the days I felt up to it, of course. I was just told to make sure I used a condom or some sort of protection, as you should not get pregnant during chemo. Not an issue for me, as I have had tubal and endometrial ablation.
Go fo it, if you feel ready :-)
For me, it helped take my mind of treatment and made me feel more normal.