Ok, I'll answer my own question....it is not recommended to take raspberry tea if you previously had a c section....here's some further info:
You should NOT take raspberry leaf tea: If you've already had a baby and your labour was very short
If you're scheduled to have a planned caesarean for a medical reason
If you've previously had a caesarean section
If you've ever had a premature labour
If you've had vaginal bleeding, or spotting in the second half of pregnancy
If you have a family or personal history of ovarian cancer endometriosis or fibroids
If you have any complications or health problems in your pregnancy
If you have high blood pressure
If you are expecting twins
Your midwife or doctor will let you know if it is safe for you to drink. They then may recommend you start drinking it when you are around 32 weeks pregnant, starting with 1 cup a day and building up to 3.
If you have strong Braxton Hicks contractions after drinking raspberry leaf tea, cut down.
Source: Emma's Diary - www.emmasdiary.co.uk/giving-birth/useful-information/raspberry-leaf-tea.aspx