Determining whether your lovebird is pregnant or not can be difficult because it will not display obvious physical changes as other animals do. Instead, the parrot will give off more-subtle signs in the form of behavioral changes. However, you can look for some signs if you believe your lovebird has recently mated and may be pregnant.
When your lovebird is pregnant, it will begin to nest. This process involves using anything it can to create a nesting area, and it may cause the lovebird to rip up pieces of paper or fabric that may be in its cage. Providing materials for nesting can also encourage lovebirds to mate, so be careful of this if you don't want to breed your birds.
Spending Time in One Spot
Pregnant lovebirds may spend significantly more time than normal perched in one spot so that they can store the energy needed to make or lay the eggs. If you notice your bird remaining stationary for long periods of time or appearing to hide out in a corner, then it may be pregnant.
Besides differences in their nesting and perching behavior, pregnant lovebirds may become more aggressive than normal before they make their eggs. In general, monitor any noticeable changes in behavior because they could be a sign of something else, such as illness.
Soon before the lovebird produces the egg, its belly will appear swollen or puffy. This will not be a significant change and so may not be obviously noticeable to you, but it is one of the things a vet will check for when determining whether a bird is pregnant. A vet will also be able to check the reproductive organs for swelling to see if mating has occurred.
If you're unsure of whether your lovebird is showing some or all of the pregnancy signs, then you won't have to wait long to find out. After mating, lovebirds can take up to 10 days to lay their first egg, and the remaining four or five eggs are laid every other day after that.