I haven't weighed myself since my last antenatal scan (DS was born 2 months ago)
I am not very big (currently a size 12), but I had dropped from that to a size 10 just before I found out I was pregnant. Casting my mind back now to March 2015 . . . I was 31 years old and had never really exercised or followed a diet plan properly. I wanted to make a change in my life, after I was told that my mum had kidney failure, which was directly linked to her diabetes. She's previously had a stroke as well. Basically, I didn't want to end up the same way, but I wasn't really sure how to go about changing my lifestyle.
I personally do not recommend diets or jumping into hours of cardio exercise per day. My goal wasn't to lose weight, and I would suggest that you don't make it your goal. Instead, my goal was just to be healthier.
I stared out by doing the 30 days of yoga challenge with Adriene on YouTube. Her videos are good for beginners. Within a couple of weeks, I was already feeling more energetic and positive, and so I started introducing 10 - 20 minutes of cardio every 2 -3 days. Exercising naturally makes me feel better, (as it does for everyone) and naturally made me make better life choices, including what to eat or drink, and so I found myself eating healthier automatically.
I didn't have a lot of weight to lose anyway but, within the first 4 weeks of my lifestyle change, my boyfriend noticed that I had lost some weight and everything was becoming firmer. The downside at the time was that I went down to a B cup lol.
I guess my point is, try to start off small with achieveable goals, and do not focus on losing weight but on just being a healthier you.
Now that DS has been born, i am able to get back into exercising again (I was getting horrible leg cramps before) and I've started the 30 days of yoga challenge again :)
I hope some of this has been helpful :)