herbalist types- why has evening primrose oil done this to my norks?

[puffling]

I noticed a reduction in pmt and sore norkage during my first month of taking evening primrose oil capsules. Previously, I'd get no soreness in the 1st part then extreme soreness in the 2nd part of the cycle. Now following my period, my norks have stayed sore-ish. Can EPO actually play havoc with your cycle? Is there any harm in taking it?

I found EPO really helps me with sore breasts and PMT. In fact my GP has recommended it in the past. But he did make me stop taking it when I was pregnant so there must be some possible risks involved.