Sciatic pain early pregnancy?

I found out I was pregnant back around July 15th. The last week or so I have been having sciatic pain which has come and gone since I delivered back in November. It started to worry me and still does that it may be related to a possible ectopic (had a previous one) but on the 29th I had a transvaginal ultrasound that I believe ruled out ectopic. There is also no sign of a gestational sac, so I am hoping it was just too early to see anything and not a miscarriage (also had a previous one).

Has anyone else ever had sciatic pain during early pregnancy and the pregnancy turn out fine? Or even have a pregnancy that was too early to see on the ultrasound and it turn out fine?