Heavy lifting you should be able to do throughout most of your pregnancy if your pre-pregnant body was used to it. The petrol equipment should be fine if you avoid breathing the xhaust, but you might want to ask your doctor. The herbicides, you should ask a poison control center or a doctor. Digging, you might want to get checked for toxoplasmosis, which is usually associated with cat litter boxes, but can also be gotten from working in dirt.
Thanx for the response, very helpful. I am going to speak to my doctor about it. I would like to keep working as long as possible and will wear a respirator. There must be other ladies out there who have been in this situation.
I live on a farm but we don't use chemical herbicides. But even organic stuff can be toxic. I would just have somebody else handle that. When I was pregnant I was able to continue lifting and digging...etc. If your body is used to it then it isn't a problem. You do have to be careful about over heating. I had to slow down in late Spring and Summer.
Also if you are dealing with farm animals then you can wear a mask and just wash your hands a lot...same with dirt. If you are mixing potting soils or turning dirt...wear a mask. It's a pain in the butt, I know.
def stay away from the herbicides, wear cloves when comming into contact with soil/dirt, no heavy lifting as this can place strain on your muscles/uterus and depending on the type of machinery used ie lawn mower/edging equip should be fine
Thank you ladies I really appreciate your advice :)