Thanks for the query to H.C.M. Forum.
Since it is very difficult to say , whether it is perimenopausal syndrome or due to pregnancy
as all these symptoms are ambiguous.
Tender breast may be in both conditions.
Lower back, hot flashes, low grade fever
all may be due to hormonal
imbalance due to perimenopausal syndrome.
In my opinion , think about perimenopausal syndrome.
Before this please get in one home pregnancy test and be tension free.